g'day i kno this has probly gone up a thousand times so my apologies, but iv got a i6 ef has 140thou on the clock (for an idea on wear n tear) and pretty keen to get over the 160-170rwkw mark. wanted to supercharge it but thats kinda blowin the budget... any suggested mods keepin it below the 5g limit? sorry if this is a repeat of old questions but if u could help me out it'd be greatly appreciated. also any info on what other ppl have done and the results? cheers

Take the head off and get it ported. While its off change the cam in it as well. Get extractors and exhaust system.
That shouldnt cost more than about $3000.

Just read through this sticky if you haven't already.
http://www.fordmods.com/forums/viewtopic.php?t=66

Not that'll net you over 160-170rwkw
You might be able to Turbocharge it for that much, but it wouldn't be a perfect job.
A basic setup, running SFA boost and using a rising rate reg would get you there.
It won't be pretty, it probably won't last, but it'll get you there.
If you really want that power, plus some to spare, save up a bit more and go for a proper turbo setup.
Aftermarket ECU, bigger fuel pump and injectors, nice big turbo, log-style manifold, el-cheapo Ebay Frount mount, and most importantly a good tune.
Internals will see a fair bit of power, Gearbox is the 'weak link' really.
Figure on about 190-200rwkw reliably and fairly easily.
Look in the forced induction forum, CHEF's thread on DIY turbocharging.