I'll second the Powermax Boondocker..........
As far as relocating your converter closer to the battery, that would not be easy on a Stampede for what little benefit you would get....if any. You would have to rewire or extend all your AC wiring, or add a dedicated AC panel. Its not like you're talking half a mile of cable between the converter and battery, at the most its 15'. I know in our Rockwood they used a heavy gauge cable out to the battery, I am guessing its an 8. I don't think shortening it any would benefit anything to the point it would be noticable.
Just get one of the retrofit kits and throw it in the WFCO housing. It took all of 5 minutes to install the Powermax on our Roo.