buy an mfi rs turbo ....

buy efi inlet and adaptor plate
ported and polished head and inlet
and uprated cam will be able to get there but newman are the best
gotech/omex/ cossy management
stage3 t3 £500 brand new
rods and pistons with bearings bolts and gaskets (use genuine ford gaskets )
decent clutch
hoses
intercooler and rad

and your half way there mate
but will need alot of this to run 250bhp safely.....

its cost me around £4k to source all of the parts to do (including a grand for my wheels and brakes) and ive got a little more to get but hopefully will be worth it.