I'd love the same info, if anyone has it. There are some good pics in the Gallery on this site--I've been studying them. Look at the Iowa buses and you can see the different approaches. Some go through the roof into the supports, and some come in from the sides between the windows. I personally like the look of coming through the top and the fact that the weight would come straight down onto the support, vs the side approach which would seem to put a lot of weight onto the horizontal bolts/screws... Someone who has actually done this would have a lot more solid info to provide.
This:
VS. This: