Congrats.
I own an Exclusive P3 for the last 11 years and have owned 2 x P10's. The P3 table is reference class.
The P10 motor controller( EM-10) is not the same as the P3 nor unfortunately in the same class.
The P3 motor and table was a cost no object engineering project by Pioneer and has significant engineering improvements and the sound is very different and quite a step up in performance.
The EM-03 motor unit was never sold separately, like the EM-10 was.
The EM-10 is still very good, but based on the Pioneer PL 70 / 50 series of direct drive motors/ tables.
It will be an exciting project you have and I will be looking forward to seeing the end result.
It will also sound great as well.
BTW, micro seiki cu-180 mat is perfect for the EM-10 platter
Few links for your reference.
vintage Pioneer Exclusive high-end turntable masterpiece with SHR motor and EA-03 tonearm
www.thevintageknob.org
Cheers