Mechanical Part Questions

[symonssoftware]

I purchased a Maker Kit and am trying to locate some of the mechanical items on the BOM but I have a couple of questions:

1. Can you tell me the bore diameter of the GT2 16 tooth gears? I measured the spindle in the stepper motors to be 5 mm but is the bore for the gear 5 mm or 6 mm?
2. Do you know a source for the 90 mm x 120 mm, Half Thrust Bearing in the United States. I can't seem to find any information on that part.

[hielsnoppe]

In general, a sourcing guide for the mechanical (and electrical) parts would be really helpful. Especially since Niryo One is no longer available from the website.