Agree with Mark on the speedo - a good device for a good price. For motors I would recommend the G Force motors (link below) that are excellent performance for not much money.
http://www.zen-racing.co.uk/catalog/...tor-135t-p-696
The other option is to look out for LRP SXX v2 or Nosram Pearl or Hobbywing 120A 1S v2.1 speedos that appear in the For Sale section here and on other sites. These are excellent speedos now out of production so available for good money.
You will be very competitive with the Sky speedo and a G Force motor but that is a £140 package so you will have to decide if that meets your budget. The other side of the coin is that buying the usual brand names could add another £80 to £100 to that and you'd struggle to notice the difference on the track. HTH
