I know that I’m nowhere near your height, but possibly of some help with regards to seat tube length.
I’m 5ft 7 with a 31.5 inch barefoot inside leg and ride a 16″ Kona Unit.
I run a 410mm Thomson setback post and a seat height of 73cm from the centre of the bottom bracket to the top of the saddle (measured straight up the seat tube) and this leaves me with 120mm of post left in the frame.
The centre to centre seat tube measurements on the Unit’s are really small. My 16″ is only 13″ centre to centre, so even with 120mm of post in the frame; it only leaves 2 cm’s below the sest tube / top tube junction.