Hey Kat how much would you want to spend?
for an extreme budget I would try and find a second hand ht18 turbo that someone is upgrading theirs.
Standard turbo for td42 and turbo manifold.
Putting an intercooler in would be ideal, you might even find a complete turbo and IC set up like this one below...
Td42 Gu turbo and intercooler kit on Gumtree http://www.gumtree.com.au/s-ad/11872...utm_source=sms
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