Yea that's what I needed. I've seen folks running 7's up front and and 9-11's out back. I'm assuming to run 11 rear springs need moving inboard? I think your right, I'd be probably be more than happy with a 215 or 225 up front.
Yes if you want to run a 17x11" out back you'd need to move the springs. At least a 1/2" offset. I've got 18x10's on my Duster with 295/35/18's using a 1/2" spring offset and another 1/2" or so trimmed off the quarter lip for clearance. That's the biggest tire you can fit into the stock wheel well, although you could run a 295 on an 17x11. If the ride height is way up in the air in the back you might do a little better, but I'd say that if you want to go bigger than a 295 you should do the full 3" spring relocation and mini-tub. And at the moment I'm not finding much for a 295 width and a 17" rim. There are some 285/40/17's, but after that there's just about nothing in DOT legal tires until you get to 315/35/17. And you'd need a 3" relocation and mini-tub to run those unless you went 4x4 height and hung them out of the quarters. Selection in the 17" diameter is getting more limited especially in the wider sizes. It's not bad up to about a 275, but after that there aren't nearly as many options.