It really depends on the quality of the tire. I ran load range D Pro Comp AT's on the stock Alcoa 16X7s. They come with a 50,000 mile tread life warranty and I got 72,000miles out of them (They were completely shot and showing belts all the way around when they were replaced). But, I had to run really low air pressure (like 39-45psi) to make them lay flat. The problems are that they squat at those pressures making them less than 34" tall and the sidewall becomes loose causing the truck to drift a bit and not corner well.
10" wide rims are more proper but if $$$ prohibit, then it's not completely necessary.
When you do get rims, consider this (cause I didn't and regret it): 19" and larger rims will allow you to run 94-97 F-SuperDuty heavy duty brake parts. The super large rotors are about the same price as our oem parts and work MUCH MUCH better than stock. But they don't fit in a 16" rim.