I have been racing the tamiyas for a while and they are amazing cars but parts were only available from hong kong etc (not anymore as j t models carry lots of stock) google them or look on here for cars and stock etc.
i have recently changed to the b44.1 and am very impressed with the quality and how smooth a car it is to drive. Also, apart from an £8-10 ballast weight, it is ready to go out of the box
(spares are always in stock at mk too)
hope this helps