I think putting 2 ACs on the roof of a Tradewind might be a bit of a challenge, and of course wouldn't work concurrently on 30A service.
You might consider sticking with the conventional roof AC in its stock location and then putting in a little "wall unit" style AC hidden somewhere in the new floorplan with an outer door that has to be opened to let it operate. It's hard to get enough cooling from that for a whole trailer, but to spot-cool a smaller space while the rest of the trailer is cooled by the roof AC it might work out nicely.
If you really want to throw money at it, you can look at stuff like the Dometic split-system setups for trucks, that offers a lot of flexibility but it ain't free!
Il Carriaggio — 1975 Argosy 24 | Il Progetto — 1976 Argosy 28 Center Bath | WBCCI# 15566
He has all of the virtues I dislike and none of the vices I admire. — Sir Winston Churchill