question: Why do you need to use 7 mics? I mean, it definitely doesn't hurt doing it but it's not necessary. How big's your kit?
As for the inputs question...hmmmmm. Via laptop, my suggestion would be to record the drums seperate (not live) with the band...I don't know of any portal soundcard USB interfaces that have 12+ input channels (they may exist, ive never seen one).
You're planning to record drums, have you done it before? If not check out my basic tips.
chezmarrone.com - drum recording tips