Help me know what kind of camper to look for.

We currently own a 2004 Flagstaff 176LTD pop-up. We bought it used about 4 or 5 years ago and have loved it, but we would like to move away from the pop-up to a regular type camper. The biggest reason is the need to raise it up and slide out the beds to do anything inside the camper like loading gear into it before a trip, then the same thing when we get home. We would also like the ability to camp in the camper while driving to our destination at a roadside campground, very hard to do with a pop-up. Also we like to camp off grid in the winter using solar panels to keep the batter charged for the furnace, so my thought was a solid camper would hold heat better than the canvas?

I don't want anything large, hoping 2000-3000 lbs, we will be pulling it with a V6 Jeep Liberty, which is rated to tow up to 5000 lbs. Eventually we will move up to a larger SUV but that will be a while, and even then we don't want a really large camper.

A lot of the campers I see in this size and weight range still have slide out beds with canvas which I was hoping to get away from. How do these hold up compared to a pop-up? Are these pretty much a must have for this size range? Will this still hold heat better than a pop-up?

There are only 3 of us, myself, wife, and currently a 2 year old, we aren't able to have any more kids so it will never be more than 3 people in the camper.

I will be shopping the used market BTW.

Thanks for your input!