the only reason we had to lower it was becasue the miltec 4 branch we fitted was hard up on the tunnel, if you fit a std MK2 16v mani n downpipe it fits perfectly, only issue is you need to weld on a lambda bung but that can be done once engine is in and running so you can get it in the right spot.
I could do the loom modification for you, as for charges I'm not sure really anyone have any inputs on what is fair?