i'm in the process of modifying a 524td manifold to fit the m20. Its NOT easy, and it requires alot of welding/die grinding
you basically have to grind off the stock mounting area and weld onto it a stahl header mounting flange in its place.
if you dont completely remove both the top and bottom mounting points (dont be tempted to just relocated the bottom holes, even though the top holes line up because the exhaust port wont match 100%)
you'll burn up exhaust gaskets pretty quickly
but if you are a good welder/fabricator the 524td manifold/turbo setup is a good starting point, but its FAR from bolt on. my entire turbo setup has cost me less then $1000USD.
includes the following:
24/lb ford cobra/bosch injectors - $112
73mm MAF ford cobra 24/lb calibrated - $60 used
524td downpipe, turbo, manifold, imported from germany from ebay.de for $150USD
magnaflow 3" muffler + high flow cat - $150 ebay new
custom mandrel 3" system from local exhaust place $100
2004 saab 9-3x front mount air-to-air intercooler $150 new
random missing turbo piping, adapters, intercooler piping, oil lines, etc - $150
total: +/- $900
the total labor for all this is reaching 30 hours though. its NOT easy custom making a turbo if you are on a budget and doing everything out of your garage. but, it can be done. i'm hoping to find the time to finish up this thing in the next couple weeks hopefully.