I use a few suppliers for Vortech parts and local car parts place can get the Gates belts, you could drop Tarmac a PM he may be able to help
Also used these guys but delivery will take a while
http://www.superchargersonline.com/index.php?main_page=index&cPath=510_1071_1073_1305_1310
That depends on your setup, how many pulleys you have and Gen1 or Gen2 -
http://www.superchargersonline.com/index.php?main_page=product_info&cPath=510_1153_1316&products_id=5012
http://www.superchargersonline.com/index.php?main_page=product_info&cPath=510_1153_1316&products_id=5011
Whatever belt you run on with the 3.33 you will need 0.5" shorter for the 2.87 pully (I Think thats correct)
Depends how far you push it, what supporting Mods and who / how it is mapped in, last year I bought a 350z with a blown engine, when we pulled the VQ lump out we found 5 smashed pistons
That was just running an after market ECU with a bad a map - was really quick ..................................................... until it destroyed itself!
So it's only safe if you do it right!!