I put a set of Jeep wheels on my Eagle and they worked great. They were 15x7's from a Cherokee, so an inch wider than the stock Eagle wheels. I put 235/75-15 tires on and had to do some big time cutting, even with a 2" suspension lift. These tires are 29's, basically. My personal opinion is that anything larger won't work unless you get silly with cutting or lifting.
There looks like lots of clearance in this picture, but when I turn I still rub a little on the rear edge.
Also, the 2.35 ratio differential gears in most of the wagons doesn't work great with the larger tires. Third gear doesn't do much until I'm over 65 mph on the highway, and even then big hills require dropping down into 2nd. And that's with 29's. If you are lucky enough to have higher ratio differentials, then you may pull it off I guess.
If I had it to do over, I'd stick with 225/75-15 as a max size.
I'm looking at your current wheels, those are 15x7's from a Jeep Wrangler I think. Are you just looking from a different style?