ok here is a nice option,
Garrett GT3071r $1600 internal gate from CRD croydon racing
water & oil lines $300-$500
manifold spacer $60
new hoses maybe-$100-200
full days labour unless you do it yourself
Full retune on Power FC
provided your supporting mods are adequate you should make somewhere between
260-290rwkw depending on what boost you run maybe 18psi
This is a rough guide but close to what it should cost but always budget $1000+ for those
just in case situations..