keendean-gt28rs eliminator kit,probably go for de-cat/exhaust/mapping/fpr
Would be a little more than £2k but not much more.
defratos-You could always have the small gt28rs rebuilt to higher specs.
You have got to think what you want ,you can't have big power without a serious loss in response.
Also there is a limit to what standard internals will take especially yours with 19mm pins. large gt28rs is about the biggest you could go with standard internals.Plus the standard exhaust manifold is restrictive so a large rs "may" not be any better than a small version rs.
A p20 is the exhaust housing or "hot side" of the turbo(ihi),having a larger area housing gives you slightly more flow at high rpm at the expense of spool up.