i do not plan to use a lipo, a 9.6v NiMh will work fine for me. the rest of your points are good, and i have had the same good experiences with G&G
as for pricing, here is what i have found roughly.
r4 carbine: 360
r4 commando: 300-320
km4 ris: 340-365
so as far as price-range, the models i am looking at are quite similar as you can see..
i dont really see the justification in the ~$60 price difference between the r4 commando and the km4/r4 carbine, the carbine has a regular stock and the extra clip holder instead, right? performance wise, they look to be the same model.. as far as the KWA, well.. like you said, KWA is a bit more pricey