I wouldn't bother with the motor mount. Especially on 2s. I just have the bearing adapter fitted and no issue so far. I order most parts from Model Sport or Wheelspin Models. MS has better postage fees. I also buy a fair bit from the US or China. It's all good just take a little longer to arrive.
+1 modelsport is fastest in the uk and wheelspin has got more parts for the pede