I bought the bundled 2.2KW WC spindle and matching VFD direct from the Huan Yang Drive shop on Aliexpress and have been very happy with it, though I cannot comment on their after sales service as I've never needed it. One advantage of this is that you know you are getting compatible components and the VFD configuration is correct for the spindle, though there will be a few numbers to change for best operation.

For cooling I simply have a submersible fish-tank pump in a tub of about 20l of distilled water and no radiator. This has been fine in tropical Western Australia and never become more than luke-warm after up to 4 hours running.

The difference in noise level between a hand router and the WC spindle is amazing. The spindle itself makes no significant noise, it's the tool cutting material and any dust extraction that will.

You mention that you may want to put the machine in an enclosure. If you do that without adding dust extraction, which will pull cooling air into the box, then water cooling would be simpler to engineer than having to force air through the box just for spindle cooling, though some small airflow for cooling the steppers/servos would be advisable.

Kit