if you're just recording yourself multi-tracked you just need like 2 inputs max. the program software will have unlimited tracks so you can layer stuff. also most programs (pro tools does) come with software instruments. meaning you'll have all the drum machines, keyboards, synths, organs, pianos, guitar sound, sound efx, etc. already, don't need to get that stuff, it's built into the recording software now. just buy an interface and a midi controller keyboard (might want mpc pads for drums) and your'e there.