I don't have a direct answer to your question but a few things to come to mind:
* Can't see this mod as a strong selling point down the road
* Smaller tank size seems very limited to me but I could be wrong
* Have you read many posts about mods other members have done? There's a great one labeled Pimp my... or something like that. Several members found available space hidden throughout their trailers.
Great choice for "Living within my means" and camping for one...
2011 Salem Cruise Lite 20RBXL & 2011 Toyota Tundra Dbl Cab
Camping History: 45 Trips / 133 Nights / 3736 Miles
FRF Social Group: Campers of the West