The 17x8 with a 5.5" should fit without any problems. I think the worst case scenario is the outer tie rod end clearance will be tight, but a 3mm spacer would be no big deal and I don't consider that a problem at all. And honestly I don't think it will even be an issue, but that clearance does depend on the design of the lip on the rim so I brought it up just so there's no surprises. I wouldn't hesitate for a second to buy those rims. As for the 245's, they aren't pushing it with those rims specs. You could run a 255/45/17 on those rims if you wanted to, although they would be pushing it because of their height (26"). 245's on those rims should be fine.
In the back, assuming you have an 8 body 8 3/4 and BBP axles, the 17x8's with 4.75" of backspace are the way to go unless there's a 17x9" available. In a perfect world you'd have a 17x9 with 5" of backspace. 5.5" is too much for the stock spring locations though. Anyway, you could run 255/45/17's out back on the 17x8's with 4.75" backspace pretty safely. And in the back the 26" tall tire would look better.