Quick quote from Richie Jute in JHB as I'm re-building my M20 (Beemer Motor) and have been phoning around.
Head Recon R 800
Sparkplug Helicoil R 120
Crank Metal Stitch R 250
Conrod Resize R 80
Block Rebore R 525
Crank Regrind R 525
Assemble Sub Assembly (3 Month Guarantee) R 850
Prices arent bad, they are in the norm of most engineering places, but thats just to give you an idea, rather call your own engineering place, for R850 and a 3 month guarantee its almost not worth assembling it yourself. Maybe its different with a CA as its a bit specialised, but they say they do about 10 of my BMW motors a month, so they know how to work on them.