8) using the stock head, i would recomend the T03 turbo from an early svo mustang or tbird turbo coupe. with the aussie head you can use a T04 turbo. engine prep for the street should consist of;
1: good rod prep. polishing the beams to remove stress risers and then shot peen them for added strength.
2: best piston would be forged, but a high quality cast piston will also work as long as the rpm is kept under 6000-6500.
3: get the crank as straight as possible, and the journals as round and polished as possible.
4: balance the rotating assembly.
5: get the cylinder bores round and straight. have the machine shop use a torque plate when doing the final honing. specify smooth bores for moly rings.
6: select a cam that, for the street, is fairly mild as the turbo will make the mid and upper rpm power. you want torque in a turbo motor to minimize turbo lag.
7: select premium components re: bearings, timing chain and gears, rings, pistons, gaskets(especially the head gasket), etc.
8: keep your compression ratio at about 8.5:1, 9:1 max on pump gas.
there is no need to blueprint a street engine. as for the head prep, clean up the ports to get rid of any large bumps, keep the surface a bit rough though to prevent gas puddling, and use stainless steel valves as the will take the heat better.