We're having a kid-friendly Halloween shindig and will simultaneously be dealing with a Phillies -Yankees game at the same time. As Philly ex pats, we are thinking about either making hoagies or doing a make your own hoagie bar.
A hoagie is a particular variety of sub/hero/sandwich that skews toward "italian" cold cuts and veggies. So you'll see some combo of salami, capicola, mortadella, provolone (sharp or not), and lettuce, onion, tomatoes and ideally some diced hot cherry peppers or something similar. These aren't mayo/mustard type sandwiches. No sourdough.
As with most sandwiches of this variety it is all about the bread. I would consider making long sandwiches and cutting small portions (easier to make) or doing individual sandwiches.
Leading contender right now is the Acme Torpedo roll. Or perhaps an Acme sweet baguette, and cutting smaller portions from there.
You might check out Semifreddi. Their ciabatta rolls are excellent although the shape aren't torpedo size, more square. They also sell a french roll but I've never had it. Ratto's deli in Oakland uses ciabatta on their Italian combo (pretty much as you describe) and it's excellent. Otherwise, Acme is hard to go wrong with. The baguettes however seem too crusty. If you're close enough you might go by their Berkeley store which has many more options.