Appreciate the comments - some are really funny by the way. in terms of materials I would use, I totally agree. I can be greener with the choice of products, like paints and stains, flooring etc, but in some cases, it is what it is. Also newer engines are not only more reliable but more eco friendly due to emissions. There is also a reliability concern, I am no mechanic. Older - especially busses that have lived a hard life seem to me to be more prone to a breakdown. Busses also ride much harsher than a nice gasser or DP.
We have owned a few Class A MH's in the past decade so I feel pretty comfortable about what I want/need in terms of a full time rig. This is also where busses typically fall short. Unless you build in storage, there isn't any.
My wife is just really hung up on the DIY, homegrown, granola type rig and isn't really into flashy, new RV's. I think there needs to be a compromise here but for me, it starts with the platform and all electrical, plumbing, HVAC etc being already there. I can modify something extensively, but from scratch, I don't think she understands that despite a positive attitude, feasibility is a huge concern. I just feel as though I'd be re-inventing the wheel for the sake of aesthetics and possible some green options - and a trade off for some worse ones.