This is the newbies forum, where questions like this are perfectly OK. As for research, this is one of many places to do some.
First things first: can you get a computer into your practice (recording) space? If you meant recording the band live, do you have a laptop you can bring with you? Does your sound guy? Is your rehearsal space the same place you store that monster amp? How are the accoustics in that room?
A USB or firewire interface will be much more flexible, I prefer PCI because it seems to perform better (some will disagree.)
Then: You'll need an interface with 8 or so ins, depending on how big your band is. How many preamps will you need? If your drummer has a bunch of mics, he might want to get his own mixer so he only occupies two channels on the interface.
Good luck!