RE: GP Ryan STA EP - Motor Suggestions
Any of the AXI motors, such as the 2808 or perhaps a bit bigger, would be a good substitute for the bog standard 600. With an 8.5x5 Aeronaut on 8-cells my 2808-20 peaked at 650g (22.9oz) static thrust, at 10350rpm @ 16.5A [~140W]. You could also use a Phasor 15/4 with a 9.5x6 Aeronaut, from which you could wring ~840g (30oz) thrust @30A [~200W].
Cheers, Phil