John,
I just got an SV-11 myself, and like the build quality. All parts minus the powertrain total ~ 40 oz, so it might be possible to build it at ~ 63 oz if configured properly.
Unfortunately, I think the restriction to use 4S battery puts you at a disadvantage here... It forces you into relatively high kV motors, which means higher current -> heat losses, and also a high-RPM low-pitch setup, which is not energy efficient.
Last year I tested a Top Flite Score ARF (680 sq in, 65 oz) with a Cobra 2826-12 (760 kV) and a 5S 2700 mAh battery. Average power required to haul that plane on 68' lines at 5.1" lap was about 650-700 Watts. I tested a APC 12-6 prop at 9000 RPM and APC 13-4.5 prop at 11000 RPM. Both flew fine, but the lower pitch prop required quit a bit more current, and ended up using up the battery faster than I liked.
But if you want to stay with the two choices you named... I'd go for the Cobra over Arrowind. (Just spent two days researching and testing motors, including those two brands).