Mods to S5 13bt?
 

Hey guys,
Im currently building up an old dx sedan and dropping a S5 13b turbo into it.
The plan is to get it extend ported, I would like a firm 300rwhp, with a solid midrange, not just top end. I would like to get into track days, and tarmac hill climbs/rallies, as well as still on the streets. So it needs to be pretty bulletproof.

Just a few questions regarding the engine...
-While the engine is being built I am looking at getting it doweled, is it worth it, what sort of boost would a non doweled block SAFELY and REGULARLY take?
-Any recommendations for a suitable turbo, and what size injectors?
-Will an OEM seal kit be fine?
-Any other recommendations?

-Also, are the secondary injectors on a Cosmo block, or series 6 any bigger than on a S5 block, and would they slot straight in?(by the way this question isnt related to the engine plans above, its for my other S5)

If you need any other info, just ask...
Cheers!