Im shopping for a spindle to my new mill project.

Now as far as ridgidety i think im fine with a bt30 taper spindle, and the spindle motor itself is only rated at 2kW.
However if i buy the smaller 30 taper spindle will i have trouble finding tooling for it? It seems to me that bt40 is more common and its the smallest i have ever used when it comes to mills.

Wich would you have picked?