This thread gets a bit confusing for me, but it doesn't sound like it's going to be a high HP build. If I read correctly, it's 280kw @ the engine, so ~225-235rwkw. I'm going to assume its a Gen3 NA MR2.
 
Since you're a mechanic, your easiest solution would be to swap to a Gen3 3SGTE. That way you get the much nicer E153 LSD transmission (arguably one of the strongest OEM 5speeds mated to a 4cylinder in the import world). Conversion price would be similar to you rebuilding/turbocharging a Gen3 3SGE with forged pistons etc etc. That mated to a free flowing exhaust (inc dump pipe), W2A I/C, ECU (flex fuel setup) & EBC. You'll probably hit close enough to your mark. Need to upgrade the fuel pump too of course. You also have the option to upgrade the turbo with say a GT28 rally potato or a GT3071 to easily reach/exceed your goal.
 
If you're a good shopper & as mechanically competent as you believe yourself to be, I think you might be able to exit for ~$6-7k.

yeah was thinking to buy the gen 3 3sgte set up and just up grade the parts i need too but i have only been able to find them in the u/s and canada out of MR2's for about 5k with out postage
and yes it was a typeo im aiming for 280kw at the flywheel
i have looked at a few builds and people have chopped and changed things to get more power, some people like certain mods others don't and some people just throw money at there engine builders to build them and go on what they think needs to be done, im on a budget thats why ill be doing it myself but i guess ill see how i go
i think how ever the cheapest option for me to do is buy a gen 3 3sgte with the E153 LSD trans and see if i can get one from a Jap wrecker i Aus
and go from there
thanks for the help guys