Guys, a wheel guy in the area has a great deal on 17" wheels but I'm not sure what tire to put on them. I want to go as big as I can but tow so I don't want any risk of rubbing. Thanks!

with towing you need a high rated tire for strength -- there are so many differant tire makes that it is very hard to tell you one kind.
now i am no tire guy but i would think a 275 70 17 would clear without rubbing .
my personal opinion on a quality tire would be a michelin .
i do know for sure the hieght of your truck either so im just guessing.

You didn't mention how your truck is set up..
If it's stock, you should be able to level the front out, and run 33's just like the SRW trucks do. My dually had a 6" lift, and I ran 35's on the stock wheels. I sold it with 30k miles, and 28k of 'em were with those tires mounted on the stock 6.5" wide wheels.
You didn't mention how wide your 17's are/would be, but I doubt they'd be any narrower than the stock wheels, so based off my experience, you should be able to run 12.5" wide tires no problem. You WILL need to run spacers however. I settled on 2" wide
Also, I towed up to 12k pounds with the tires I had(BFG ATs..."D" rated)

You didn't mention how your truck is set up..
If it's stock, you should be able to level the front out, and run 33's just like the SRW trucks do. My dually had a 6" lift, and I ran 35's on the stock wheels. I sold it with 30k miles, and 28k of 'em were with those tires mounted on the stock 6.5" wide wheels.
You didn't mention how wide your 17's are/would be, but I doubt they'd be any narrower than the stock wheels, so based off my experience, you should be able to run 12.5" wide tires no problem. You WILL need to run spacers however. I settled on 2" wide
Also, I towed up to 12k pounds with the tires I had(BFG ATs..."D" rated)

The truck is just stock. The thing about spacers, I've been worried about them. People tell me it starts messing with the hubs and relies on the studs instead of the hubs to support the weight. I guess I need to do more spacer research.

The truck is just stock. The thing about spacers, I've been worried about them. People tell me it starts messing with the hubs and relies on the studs instead of the hubs to support the weight. I guess I need to do more spacer research.

Yeah there is a bunch of use that is running Fred's 2" spacers and pulling heavy. Those things are well made. I'd be worried running some off brand eBay spacer though. There is alot of good reading over in the Dually section about tires sizes and spacers.