Topicstarter, I see four ways to have BGA

Topicstarter, I see four ways to have BGA chip with usable for installation balls:

1) Buy new chips - they're coming with balls (as refurbished chips)
2) Buy special trafaret and BGA paste (laser-trafaret.ru, gsmservice.od.ua and others)
3) Buy a pack of balls - it's very useful if you have desoldered chip and need to recover only small number of balls
4) Train your skill to remove chip with all balls on it. It requires some time. I can give you 4 small advices:
a) use flux
b) (I'm assuming that your chip is above your board during desoldering) try to desolder chip with a maximum temperature of board (bottom) and minimum temperature of chip itself (top) - by this way you can get all balls on chip.
c) be sure that all balls are fused before remove of chip
d) and of course, use good heater sources on both sides of board ("good" means they must have enough power, heating area and good temperature control)

About thickness - I think 0.6mm will be quite enough.

I like name of topic