Shower Invite List = Baptism Invite List.....lots of people. Ideas?

I don't know if this is true in any of your cultures, but for us anyone you invite to your baby shower must be invited to the baby's baptism. (we're greek orthodox). Soooooo....big fat greek family = big fat greek baby shower! It was amazing, my mom and MIL planned the entire thing and SIL decorated. Everyone was there! But we do have a huuuuuge family, and even keeping the guest list to a minim we had 72 people show. Wow!

Now my question is this: does anyone have suggestions for the baptism? Is there any food/party related etiquette I should tread carefully around? Fitting everyone in the church, assuming they all come, isn't an issue. I'm more concerned about what to do after. Usually people have a brunch type gathering after the baptism hosted by the new parents. Now our house is out of the question because we live an hour away from the church. MIL lives very close, just down the street, and might be able to fit everyone if we have tables set up outside, although that would entail a lot of work for us. The baptism will be around july, so a BBQ-type thing could work. There is also a formal banquet hall attached to the church so we could host a brunch there, but that could get very expensive very quickly (no church basement for buffet type things available). What do you suggest? Catered event at MIL's, bbq or buffet-style? have a later in the afternoon baptism and do just cake and coffee? pay for the formal banquet hall and do maybe just appetizers, desserts, and coffee? What would you as a guest prefer?    Thanks!