Sounds ambitious, also sounds like you have a good handle on it. My only question is why the oil primer? My concern is the temp fluctuations and the fact that oil won't flex that well on metal under hot Texas sun and cool nights. Personally, I would spot prime any exposed aluminum and two coat with finish. I would go with a Ben Moore system, they have a latex primer that will handle the exposed aluminum and their Moor line of exterior paint has excellent adhesion qualities. The Moor products will grab on to that with a death grip, and with spray the siding will look factory finished. I'm sure the other top manufacturers have comparable systems but my experience is with BM, and I wouldn't recommend anything but the top line products on exteriors. If you can carry the extra cost, the results and peace of mind will be worth it.