For sale is an homemade spindle cartridge. It consists of 3x 6004 bearings rated to 24000 rpm, cleared of grease and require a drop of light oil every half hour, An er25 extension spindle and an aluminium housing.

CW about 10 feet of green polyeurathane drive belt.

This has about twenty hours on it at 11000 rpm with no issues....there is plenty of metal there for drilling/tapping other mounting options.
Any questions ask
Some pictures. Got to be worth 50 delivered to UK.

...and thanks MYCNC for the slot