(Over_Easy @ Mar. 29 2007,13:56) I'd stick with the same brand front and rear if I was in need of both. I would go with a better tire than the BT56 however, especially when your only looking at $50 for the front and not the rear - it's not like he's giving it to you.
Most will go through 2 rears for every front tire. I'm currently running the new Metzler M3 rear w/ my stock BT56 front. Unless you plan on doing some serious track days it won't make a lick of difference running two different performance types of tires front and rear. And I get into the twisties pretty damn well with no ill side effects.
Front and rear operate independent of one another and each is controlled by you, the rider. One free rolls & one is engine driven, each have independent suspension and braking systems as well.
As a FL rider, IMO, I would go with the Avons. The high arched profile of the M3, MX Pilot Powers, Dunlop QUA, etc. will wear the center tread out right quick down here and the Avons have more a of a rounder/flatter center. You will get more miles out of the Avons although I have yet to try them myself...they will be my next tire.