How big a tire and a proper balance of handling for a more neutral feel is also dependant on which tire you run.
Sounds like the thread starter here is going with something like BFG's or maybe GT-II's. He NEEDS 295's in the back with those low traction non-sticky type tires. The rear end will get loose, he will not experience understeer with these tires. Go BIG in the back to keep the rear end planted (good luck with that).
One might consider SMALLER in the front in hopes of moving toward under steer to balance the rear which WILL have over steer.
Avons, Bill Boards and other sticky tires will call for different size's front to back for the balance.
I have two sets of wheels and tires, Goodyear GT-II's for the street and Goodyear hand grooved slicks for the track. On occasion I drive the slicks on the street, like today. The difference in "confidence" in the car is night and day. With The GT-II's I'm ALWAYS on the edge of loosing traction and cannot relax for any shift or any corner. They will get away from you in a heart beat, rear end comes around, or they just go up in smoke with a bit to much throttle. Running the slicks, I never worry about the next shift, in or out of a corner or in a straight line. I KNOW those tires WILL bite unless I'm deep in the throttle and being stupid. NO WAY that rear end is coming around unless I want it to with throttle over steer. It's FAR less stressful driving on tires with traction than without.