Haven't got that far yet. I know I want to go with a angled seat hoop that fits the curves of the back of the hump. From there I'll build me a pan for all the electronics and some kind of set up for mounting.
From the pics I've seen I haven't seen one mounted up with a hoop, most are just the stock rear frame section.
I'm really liking your build man, Gives me some inspiration for mine. Mine will be a lot more slow going. Can't wait to see how your alloy bcr seat turns out