Welcome to the forum!
The manual for the VR-355 lists the allowable speaker impedances as 8-16 ohms. It's possible that it will handle those new speakers, but it's a risk.
I'd like to say that your new HT963TA has far more advanced surround sound decoding than does the VR-355. If you're using a source with six-channel analog outputs, then the VR-355 might be a decent option because it has six-channel analog inputs. Without those outputs, though, I'd probably pick the HT963TA. It's inputs are limited, but it does have an digital optical input - which can't handle the new lossless codes (like Dolby TrueHD), but it will handle Dolby Digital and DTS just great.