Why not get the same spindle as you have, they are all much the same some are built slightly better, but not enough to pick one that is better than the other, a correctly programed VFD can work for many years changing the spindle for the same spec spindle won't need any changes to the VFD Drive or a replacement of the VFD Drive
A spindle with ceramic bearings is going to be the best choice, and one that has a Grounded 4th pin in the spindle connector, there are some that detail this, so for the standard 2.2Kw 24,000 RPM spindles there is not much that sets them apart
So just 3 things to look for
Ceramic Bearing
Spindle Plug Grounding
Higher Torque with lower speed minimum speed 3000 RPM (Which have a larger and longer Rotor and Stator ) and are a true 2.2Kw