It might not be nessecary to mention, but remember cleaning, oiling and comm cut. If you got the tool, align the brush hood. That makes a huge difference, as far as I understand.
I believe the choise of motor, depends quite a lot on personal driving style - unless you're able to adapt to the proper motor for the track.
Schumacher Mi5 - Sanwa MT-4 / RX-462 / KO Propo PDS-2123 - Nosram 5600 X-treme Saddle Pack - LRP SPX Zero/X12 17,5 - Nosram Stealth Touch Evolution - MAAS SPS 9250