Well if you want a project you have come to the right place.
The W124 is great from a suspension standpoint. Lowering springs, better role bars, better brakes are all availible for them. Heck you could even go nuts and convert to a 500E suspension with Brembo brakes and some massive sway bars.
Now for power you will want to talk to the Finns. Talk to Dave(GSXR) he is active on their forum and he can probably help you as well.
Pretty much if you don't want too go to radical you can add an intercooler and bump boost up a bit. If you want some serious power though you will have to add a much larger turbo, with a massive intercooler, and have some custom mods done to the IP. But think 400hpish!
