If you want a margin of safety and handling, definitely look at a dually. A typical hardsided camper in the 8-9 foot range is likely to weight over 2000# dry and probably close to 2500# wet. You will want some addons such as solar, a couple of large batteries and a generator. With food for a couple of weeks, tools, lawn chairs, clothing, food, kitchen gear, etc you are likely to be in the range of 3500-4000#. That probably sounds like a high side estimate, but not so. My 9.5 ft Northstar Igloo is 4400# when ready. That is at or beyond what most 3500 SRW trucks can handle.
BTW I strongly agree on a couple of your specs. A wet bath works well. After baths, I spend about 1 minute with a squeegee and the bath dries quickly. Slides are heavy and typically provide little useable space with another downside that most of the slide campers are not useable unless slide is extended.
