Given the parameters you've laid out, the MFJ-1662 is the first thing that comes to mind , possibly on a "clamp on" Mount either on the hitch or off the rear frame / bumper .
I would also recommend taking along a ground rod and some #10 stranded wire to help the antenna and a SWR Bridge of known repute .
As to power supply's, It won't hurt to connect to the house battery with a good trickle charger to keep it topped off , but most of the HAM type PSU's will do well as long as what you get is rated to carry the TS-480 ( check E-BUCK and Craigs List in your area, sometimes you can get a good deal there) .
The above is pretty basic (quick & dirty) and low cost, you will just have to decide for your self how you want to modify (refine) the operation from this point , there is no "one size fit's all" here , every install is a bit different according to taste / operating parameters but you will just have to play with it to see what fit's your stile.
I will suggest that you try it out at home quite a bit before taking the system on the road (campground) so that you can see just what needs to be changed or tweaked and you have tools and or parts available to do so.
DE: John W9WLS