Having owned two truck campers, I would blow right past the 3/4-ton (250/2500) and only consider 1-ton trucks (350/3500.) Without slides, you're probably ok with a srw long bed, but if you get up to the 11-footers, many folks would likely suggest a dually, because of the stability. In short beds (which is what we own), srw works fine, even with a slide. Our camper is around 4k-lbs loaded and our truck handles great! Others will have to chime in on the weight of long-bed campers without slides. My guess is they will be at least 4k-lbs too.
Although short bed trucks limit the selection of floor plans, they make for a easy to manuever truck and a decent daily driver.