Setting up a studio.... volunteer seeking advice

My intro: The title gives the story away really. I'm a volunteer serving here in the Kingdom of Tonga. I'm working with the local radio station to setup the nation's first record label, exciting stuff! I have a little bit of experience using a PC recording setup from my days in a punk band... but we're shooting a bit higher here. I'm looking for advice on setting up a studio using a MacBook..... we're starting from scratch. Please keep in mind that we're in the middle of the South Pacific, with no music shops... no tech guys.... just me, a radio station owner and some local boys wanting to start recording! We're looking to use a Mac program on his MacBook and wanting to invest in a firewire interface. We'll be recording mostly with traditional 'rock bands' (4 piece bands with a full drum kit)

My Questions: We have a compact mixer (Phonic 1722x) in the studio. It has 5 mic lines in as well as inputs for keyboards/midi devices ... can we run this mixer through a firewire interface (say a 4 line input) to add extra channels while recording? This would save us from buying an expensive 8 input firewire interface.

What software do you Mac users reccomend? GarageBand seems to cover the basics, but only has 8 possible tracks i hear?

Any input would be GREATLY appreciated! Thanks! (or Malo Aupito as we say in Tonga!)