Front, depending on the backspacing, you can fit up to 245 and I have seen 315 on the back but the car had mini tubs and a 4 link system. I have 255 in the back with a 4.5 backspacing and they have a lot of room...close to the lip though Most likely will bring it back down to a 245 (since I have dropping the car 2 in). If I remember I have a 5.5in backspacing in the front and mounted some 205 (again because I am dropping the car 2 to 2.5 in in the front and want as much clearance as possible). Hope it helps.
17X8 front 17X9 rear. get the correct spacers and you'll be fine with any rubber made for those widths. The 315s are too wide I'll say, and 275 up front is a bit much, perhaps 255 front and 275 rear but then you cannot rotate the rubber either.
I say go get a stock set of late-model rims that are all 17X8 and use the stock sized rubber 245/45-17 at all four corners and you'll be good to go, even with moderate lowering.