This info probably won't help you very much & in a nut sack, the answer is: I Don't Know.
However, I've used audacity, but I switched to Magix Music Maker & it works 10x better than audacity (for me). It's a freeware download you can get at download.com , BUT it's a windows based piece of software, so you'd have to repartition your system & run some form of windows OS.
Whichever system you use, running 2 mics is Not going to improve sound quality & I don't know that they would play on separate tracks - if That's what you're shoot'n for. I recommend either doing each track individually OR make the 1st track with both voice & guitar using 1 mic, then going back & overdub the lead guitars & harmony vocal tracks using the right &/or left for stereo effect.
If you'd like to hear an end result of doing all tracks individually (in this case only 4), go to http://www.soundclick.com/bands/default … dID=525907 I think this link will work; if not search for jwildhair's follies & give a listen. "***(take 2)" uses 4 tracks & the other is guitar & voice on a single track.
If there's not a reason for it, It's wrong.