Glass beads - what size to use and where can I get??

Hi Guys,

I recently got myself a blasting cabinet. I'm looking at getting glass beads but not sure what size to use and where I can get.

I see on Blastrite's website they range from:

Code: BL, Size range: 400-800 microns
Code: C,  Size range: 200-400 microns
Code: AB, Size range: 200-300 microns
Code: AC, Size range: 150-250 microns
Code: AD, Size range: 100-200 microns
Code: AF, Size range:  70-150 microns
Code: AG, Size range: 50-100 microns
Code: AH, Size range: 40-70 microns
Code: AQ, Size range: 1-50 micron

I'm not sure what size to get. It will mainly be for motorcycle parts, so not looking for a rough finish, more smooth like.

And where else can I get the beads, Gauteng area?

Dankie