All the current river runners are fine boats. (Mamba, Remix, Burn, Zen, Diesel, and more).
Buy a boat according to DBK.
First the boat needs to be comfy to you. You need to be able to sit in the boat for 3 hour without your ass/legs/feet killing ya. Some times the boat can just be too big in the cock pit and you have a hard time with reach and lifting your butt. So if you are comfy that's number 1.
Next, you have to love the boat. Maybe its the sexy lines, right color combo, band??? For whats its worth, the more you like the boat the more you will boat and the better you'll get. So, your opinions matter, Buy a boat for your own reasons and don't tell other push you in an uncomfortable direct.
When buying used boat, bring a flash light and really look all around. As far under the seat and outfitting as you can. Look for cracks where the outfitting/pillars/seat makes contact with the hull. Make sure all screws will loosen and tighten. Make sure drain plug is in good shape. Look for discoloration and sun fading in the plastic.
Once your find a boat that meets your needs, don't be afraid to pull the trigger. Good boat don't stay for sale long. 90% on the boat on CL a garbage.
As to over nites camp, if you go lite (less then 30lbs) then most boat will go. Over 30lbs and you'll need a boat on the bigger side of things.