there's a custom gt2860 kits for sale in the FS section. he hasn't got pics yet but he only wants 1k iirc
 
or i may know of an ATS gt2860rs kit coming up for sale.
 
so what igniter have you got? you may need a tacho adapter, i have diagrams of how to make one to suit the gt4 tacho if your running individual coils, but dunno if that's applicable to you.

Do you have different injectors & pump? If not, get that & upgrade turbo. Should see great results if tuned well. They can prolly sort your tacho too.GT28 or even better a GT3071 would be good.

All at the same time. I doubt you're running out of fueling right now, so upgrading injectors/pump & retuning will get you no gain. Changing the turbo along with it & revisiting the tune will bring it all together You also avoid doubling up on tuning costs.

So I got in contact with the bloke who owned it before the guy I bought it off and it had a rebuilt LSD gearbox in it as we'll as a high flow turbo (if that was switched over when the engine was). He also said it hasn't had a proper tune yet and that its running crap, which is still good so I can't wait to see what happens when I get bigger injectors and fuel pump and then tune it.