Common BGA stencill size and ball soldier size?

[u666sa]

For a beginner, if I'm going to reball some notebook video chips and computer south bridges.  What reballing stencil size do I need -- width length, hole size?  What size ball soldier do I need?  What is the most common chip sizes I'll encounter, as far as width and length?

I'll buy stuff as I go, I guess.  But I need something to start with.