Tire size suggestions

[custom1970]

I know i've been off a while, but have had some other projects going on lately. So took the truck out last weekend and the steering wheel was shaking like crazy. Got out to check my front tires and noticed that they're coming apart! To bad to even drive to a tire shop. Anyway, since I need 4 new ones (backs got bald somehow anyways) I want to change sizes. I currently have 235/50R17 all around. I've never liked the way they've looked. I'd like to have a taller tire in back, and the same or maybe not as wide on the front. Having a hard time finding the same tire in the sizes i'm looking for. Closest i've found so far is Nitto NT555 275/50r17 for the back and Nitto NT555 225/50r17 for the front. I'm basically wanting to fill that big void over the rear tires. Wondering if anyone has ever done this, or has any other size suggestions.
Thanks, David