You are overthinking this not because you need to hire a pro, but because solar is not something to be planned in details before purchasing an RV.
When you get your bus, go on the roof with a few 40"x65" sheets of cardboard - a typical size of 230-260W panel - and see how many you can fit safely. You need to be able to walk on the roof around the panels, and there are tall structures like A/C, and clear lids of "sunroof" that can't be covered.
330AH/10A = 33 hours discharge to 50%, but this isn't everything. 10A @12V is basically pumps, lights, TV and laptop. When you run 120V appliances, you draw 100-150A @12V and battery hates this, responding with a reduced energy available, i.e. at 100A it will last not 3.3 hours but only 1.5-2 hours.
It's hard to tell whether you will be able to recharge battery with 800W solar. If you don't run any powerful 120V loads, you should be alright with as little as 500W. Now, try telling DW that has just washed her hair because it's been raining and nothing else to do - try telling her not to use 800W hair drier because battery is low :)
