Don't buy that Schiek one. You can't go wrong with a leather, single prong , 10mm one. I've got one from a random Canadian manufacturer and it's working well.
Something like that : http://www.inzernet.com/detail_belt.asp?PRODUCT_ID=FOREVERBELTS_BUCKLE10MM
Model 6011 Single Prong Competition Power Belt from Schiek could be fine too bit it's a little bit too thin *9mm*. Best advise would be to invest in a good 75-90$ belt , it will last a while and it's a very good investment.
Eason: I can squat 315 x3-5 on any day of the week but I'm still leaning a little too forward. I'm presently working on getting a stronger overall squat and be able to squat 315x5 with almost perfect form.
It will really depend on a few factors: do you have a coach that can rapidly correct your form? Do you eat and sleep well? Did you find the technique that fits your body and that you like? etc. For me, I had to fix my technique, fix my starting position, get stronger, etc. Once I've started following guides from raw lifters (IPF, Supertraining(Mark bell), the crew from Juggernaut system, Candito and similar) and not from Westside Barbell, I've started progressing much better.
I guess it took me like 8-12 months to get a good 1 rep 315 lbs from a solid 225 for reps. I don't progress very fast though and never had a coach. It would definitely help. Would have to check my training log to confirm.
Hope it helps.