I love the look of this frame, but I don't think the cross bar will allow room for an engine. Would cutting out the cross bar make the frame weak and need bracing?
I do not think they would have just put that bar there for "style"...I am pretty sure that is part of the frame support...I don't think that could be cut out and still be a stable riding platform...Especially with a motor strapped to it...Go with the already tried and true Hyper, like you were already thinking of anyways and for only half the price.
It's become the first thing I look for when looking at potential bikes for a build. So many bikes I have looked at that were darn near perfect for what I wanted all end up being Aluminum frames. It's honestly kind of annoying.
Speaking of semi-affordable cruisers I have looked at for a build. I really love this one. It's not as budget friendly as the Hyper, and the durability is unknown. I just love the color scheme and the front and rear racks. It also happens to be a 7 speed.