I have not seen the white vinyl, but all the vinyl finishes are really good.
There is no way to avoid GST on any retail purchase.
No need to worry about damage. I picked up my complete HT from the outlet and have only found one minor colour flaw (a VERY small off colour spot) on one speaker.
Yes there will be an improvement in sound quality over cheap speakers. I would trade off a few Hz on the bottom end for a huge improvement in overall sound quality in a heartbeat.
Check the hearing things forum to see if you can find someone in your area that will give you an audition.
