I'm thinking on acquiring a spindle+vfd kit, but I'm not sure between;

a 1.5kw spindle ER11 water cooled
or
a 1.5kw spindle ER16 air cooled

The price is similar, water cooled costs 20€ more. My goal is to mill wood fins. wood molds, and foam boards for later fiber glassing.
I might be wrong, you can correct me;

ER11 - more precise for wood molds.
Water cooled - more silent, keeps spindle cooler on hotter days ans longer hours of work.

ER16 - much faster for milling large foams. Less time and energy consuming.

If I could put some sort of adapter to transform the ER11 on a ER16, the problem would be solved, I think.
https://pt.aliexpress.com/item/1-5KW...269339550.html

Cheers.