I am a bit late in my reply but I have done the transplant.
I have a nice lorinser kitted car fully lowered and did not like the look of the cosworth. I too wanted the extra power but not the dog box, so in with the cosworth and stayed with the auto. I did have a few problems as no full car to rob and parts hard in newZealand, rev limiter, new tacho etc.
It works fine and I love it, I am just having my box serviced and upgraded to improve the shifting. As for the self levelling susp I know of a couple of guys who had to take it out due to problems with repair. Who knows but if you dont mind the look of the cosworths I would buy one.