As for suggestions like others have said yes an elevated sleeping platform would work best. I'd like to just dive in and sleep especially when I'm on a road trip and it is late. I also really like the slide out kitchen! Here in BC I find it pours more than the sun is shining and if I would be able to possibly do some cooking inside with the windows open for ventilation I would be a very happy camper indeed

On that note I'm thinking maybe having the interior being able convert to a dinette would be ideal. That way with the table down you would have your elevated sleeping platform with storage under it but in poor weather, the unit would be entirely livable and very usable more so than just having a bed in there.
You may have said it and I probably missed it but do you have any idea of a rough weight you are looking at for a final version?