Look at the suspension options when buying your truck. Many of the 3/4T and 1T trucks use the same power train but use heavier suspension in the 1T. My F250 pretty much runs the suspension as the same year F350 (except for the taller rear axle block) because of the option packs I chose yet is still rated under 10,000 lbs to save me on licensing fees and insurance. Once you get in to the dual rear wheels, there are other differences - However, many 3/4T trucks can be optioned to closely match 1T single rear wheel components.
BTW: My F250 has the same tow ratings as the F350 SRW (you just have to be smart about how you handle hitch/pin weight).