hi all. what is the differnece in the Hyper 7 PBS and the Hyper 7 PCR? Is there any differnece between speed and overall performance? And which is the BETTER one out of these two?

Also, does anyone know what is required to turn the Hyper .21 8-port engine in a pull start engine, so i can use both starter box and pull start, and the price of the items required?

And does anyone know any good UK sites that sell hyper 7s, accessories and everything else for a nitro car?

thanks everyone!
sorry for asking so many questions!