It really depends on what else you're serving. Is the po-boy station the only food being served? Is it self-serve or will you have employees preparing the food? 4-8 oz. of meat per person would be a good starting point, but also keep in mind the size of the bread and quantity of garnishes.
A few thoughts
it depends on the budget, if it's the main event and you are only getting $10.00 per person you are in deep doo doo, but if its part of a larger spread you can get away with less food
the average reception/buffet service is 1 to 1.5 hours if you are cooking po-boys to order at the station you should be able to control the flow and not run out too quickly, if it's a build your own good luck you have no control at all
How fancy is the event and how easy are these po-boys to eat, if it's a stand up reception with ball gowns and penguin suits you can probably get away with less, if its a Frat boys convention and chug fest you are totally screwed
How big are the buns? 1 bite? 2 bite? honestly my best guess without more information is to plan on serving 4 single bite and probably 2.5 two bite po- boys per person, I would advise that you get some kind of guarantee on quantities and expectations from the client before committing, say that you will be supplying enough assorted seafood to fill this many buns, that way you can figure out how much to purchase and prep
good luck and post pictures I think we would all like to see how iy yurns out
4-8 oz pp is the usual portion for protein but all bets are off when you are serving seafood.
Left to their own devices some guests will overstuff the rolls (for a mealtime event 6-8 inch French poboy rolls are usual) with one or more of the choices then fill in the leftover space on their plates with the other selections unless some sort of a control is in place.
Start the buffet with whatever sides are on menu (a couple of different slaws plus FF are classic seafood sides) then the rolls and shredded lettuce tomato pickle chips and slivered onion for the guests wanting "dressed".
This leaves the seafood at the end of the line.
I would recommend to the host to have someone standing guard over the protein with a pair of tongs and a smile ;-).
How to divvy up these particular offerings pp is up to the guy with the checkbook (I admit my lack of knowledge when offering more than 2 protein choices) but maybe @chefbillyb or @meezenplaz or @lagom will swing by and share from their seemingly endless amt of catering knowledge.
First of all I wouldn't have a Po-Boy bar. This is a nightmare for food falling all over the place. If anyone has ever made a Po-Boy, it's messy with items falling off and out of the bun. This happens with people who know how to make them, never mind having people walking through a " Make your own" line.
I would make up Po-Boy sandwiches and cut in 1/3 portions with toothpicks keeping everything together. This way people can walk by and take a portion of what they like or a tasting of two or three different varieties. There are somethings in catering you should control. This is one of them.
Catering is a two way street, you always want to give the client what then ask for. You also always have to explain to the client the best way to accomplish what they ask for. I always opt for neater, cleaner and easier ways for the guests to enjoy what I cater......ChefBillyB
Wha-? I thought I sensed my name being invoked.....
Ahh, I see it was the irrepressible Mimi, again seeking wisdom on the behalf of others...
Well most of it has been said, but first, with Oysters and Crawfish I'm not as concerned as I might be had it been say, crab and lobster. The shrimp however, I do envision greatly outweighing those two in popularity, I would therefore anticipate a heavy demand on that. And shrimp isn't cheap anymore, and I agree with Mimi and Billy that any seafood buffet must be regulated. (and for some reason chopped fruit as well--they always just INVADE the dang fruit bowl.)
The sides and condiments can be put out self serve, and of course FIRST. Basic rule in event catering is to get as much on the plate first, before the guest hits the protein station. This helps prevent the last 2 dozen people in line screaming like banshees cuz "the meat's all gone!" while 48 fingers all point at YOU, instead of their table mates with piles of seafood heaped on their plates.
There are a couple ways to do a seafood sandwich buffet so it still "feels" like a sandwich bar....
The first is as Billy suggested, MAKE an assortment of small sandwiches for the self serve buffet, and again,
put them as the last selection. (If its a line, this will work, if they're "stragglers" they may well go for the sandwiches
first.) If this still doesn't feel right,
The second way (and best IMO) is to offer their bread and garnishes on the self serve buffet table, they transition to the attended buffet action station, where you or your pleasant servers will gladly heap up (per your portion control) their open bread with the meat of their choice.
As a side note, you WILL get people who aren't happy with how much you put on their sandwich--in those case, you just.....add a little more. The'yre happy, and sure, the guy behind them may notice and ask as well, but that "trend" will end shortly--you're not out much and you have satisfied another basic rule.....try to give the guests what they want.
All that said, price being paid is indeed a factor in food quantity planning as well as the HOW its going to be served.
Again as said, these things are up to you to explain to the client, so you don't paint yourself into a corner.
An additional thought, Billy is correct about the incredible mess "loose" fillings make in a self serve buffet.
And "mess" equals waste. No one cares about wasting lettuce or bits of chopped tomato or spilled salad dressing, but wasted seafood, even in minimal quantities, should be avoided. Its similar to my having served Sloppy Joes a few times.
The ONLY way to do this is for the guest to bring the bun to you, and you slap their Joe-Goo on it for them.
Maximum control with minimum mess.