But the mount you linked would fit?

https://www.amazon.com/Spindle-Holder-Bracket-Engraving-Machine/dp/B07QXRKQ19

A 2.2kw spindle should be plenty. I had a 3.2kw on mine and never came close to reaching its limits. I use a 2.2kw now.

If you get an 80mm one with this style of mount, the holes line up perfectly to the back plate of the Z axis, and you don't need an adapter from Avid. Which is good because the adapters for holding spindles from Avid are terribly designed. Mine sits in the spare parts bin.

Ps. bonus of getting an 80mm 2.2kw, is that replacements are dirt cheap and super available if you need a backup. larger ones are harder to source and replace.