What Hacker instead of GWS A drive motor ?
Let's see... GWS A drive is a 280?
I think that the AF 010 would be a good replacement.
More power and still fairly light. The 801P is the 010, a Maxon 4:1 planetary GB, and a 10 amp ESC and runs around $140.
AeroMicro.com has the same motor and ESC mated to a GWS gear box for about $135.
The only Hacker would be the B20 and it's more powerful and more expensive... about $210 with ESC.