You would need a well spec'd top end with cams and 26mm ports.
bottom end is a low comp piston and rod setup around 7.8:1
oil jets 10 studs core plug retainers decent sump and breather
Using a decent turbo like the gtx or gt series even the bw with around an 80a/r housing is the basis for what you want.

head i would use cnc heads Rick wood.
block machining pete mason.
Balancing in Heybridge
Assemble using decent gaskets and motorsport bearings.

Burtonpower have new small core 205 blocks with billit main caps all machined with studs pump core plugs etc etc all done at a very reasonable price.

Nothing that hasnt been done for many years by lots of people and tuners.

Not many secrets or unknown stuff now days.