Size wise, it's hard to say based purely on height. I'm 5ft 11 and ordered an 18", Lookmanohands on here is maybe an inch shorter than me, he's on a 16" which to my mind looks a bit small, but he likes a very chuckable bike. He's also running a 90mm stem iirc, whereas I'm putting an 80mm stem on mine.
Oh, and another factor, I've got a fairly long inside leg length, even with a 410mm Thomson post it would have been on the min insertion line for me on a 16" frame. There's only 18mm in the top tubes, but 50mm difference in the seat tubes. I normally run a 23" Top Tube on my bikes with a 90mm stem, but figured I would be better off with the slightly longer 18" frame and a 10mm shorter stem to give a slightly roomier cockpit.
50+ mile rides on an SS bike though! 😕
The 2 main factors you probably have to consider are the weight (29er Inbred is almost 6lb frame, the Scandal is sub 4lb iirc) and the SS compatability (Scandal no longer has slot dropouts, and to run SS on one you'd have to use a tensioner).
Both can get a fairly big back tyre in there too, and 29er wheels give you a fair bit more cushioning than 26" do anyway, so frame material is probably less critical to comfort than on a 26" hardtail.
Oh, and the Purple Inbred is bloody gorgeous by the way! 😉