i would suggest keeping the a/c unit until exhaust all the options. if you could post a photo or schematics showing your roof layout, we might be able to offer some pointed suggestions... on my roof, i could fit 7 or 8 of 240w panels, but only installed 5 so far with total 1200w, along the periphery of the roof. my panels are sunpower, which boasts the highest efficiency in the industry with relatively small footprint. the only trick i did differently than others - for the outer brackets, i installed them with the bottom of "L" inward.
2000 Country Coach Intrigue 40'