While it's exceedingly easy to assemble from parts purchased on line and save a bit of money, Adventure Pilot/iFly sells one too and for only $199.99. https://www.iflygps.com/STORE/Product/stratux
Is it still true that symthetic vision will only be availabe on the 740 and not the 720?
Yes, this is the case. However not for lack of trying - the 720 just didn't have enough horsepower to support synthetic vision.
+1 on this one. If there was a trade in program for the 720 to 740b, I would already be at the post office.