I've got the standard MY98 sigle din and black controls as per the standard UK turbo. What i could do with is the double din layout; can this be changed easily, and where can i get one?

Thanks

you mean you want to change your single DIN to a double one?
On your My98 is that the same interior as a MY99?

If so, yes it is possible!! I am currently still in the process, what you need is a surround of a japanese, US or Aussie car.
The second thing you need are the heater controls brackets also from jap, Us or aussie car. these are not really necessary but without them it will look cr@p when your controls are lying too much inwards...

After that you will have a double DIN slot