There were a bunch of guys in the bay area that used an e55 motor to make there own c55. They had to replace most if not everything. And judging by your car being a 96 with the 4 speed you'll have to change out the tranny as well.
Try looking around the old classifieds on the site for their post about how much they were charging to swap in a 55 motor plus parts.
They were also trying to put a slk32 motor in a 202 as well.
Its somewhere about a couple months ago.
Edit:
Looks like they were asking 15k for the engine swap alone with a reprogram of your computer as well. But the tranny would be extra.
So I guess you would figure sine you would need a tranny for your 96 youre looking around 20k and some change to get a c55.
Best bet is to start with a 99 C43 and work up from there.