Originally Posted by
cyclezen
...
the longer seatpost available these days menas you can downsize the frame and get the shorter TT and still get enough saddle extension...
This.
Focus on getting the TT right, and the rest can likely be adjusted by the amount of seatpost you have extended. ( and the amount of setback in the seat post)
Also, if you already have a bike that fits you reasonably well, take the measurements off that and star working from there.