Anthony,
Westerbeke makes small self-contained permanant mount gas gennies ushually a 3.5 or a 5.0 suffices for a 30' boat although if your overnighting and running A/C and halogens for night fishing you'd probably want at least the 5.0 if not a little larger. I've toyed with the idea of putting in a gennie and a reserve tank 40-50 gal dead center or two 25 -30 saddles. Please post as too the results of your search and estimates for installation