Speak to Mark at GTPumps
http://www.gtpumps.com.au/
They have the EVOIII TD06SL2-20G and EVOIII TD05H-20G...never had any experience with either turbo but know Mark is pretty clued up. With the AUD-GBP exchange rate they are quite affordable too...alternatively have a look on the US DSM forums:
https://secure.buschurracing.com/cat...roducts_id=932 <- pretty sure this is bolt on subject to minor mods but im sure David will help you out.