hi mahleu,
You will enjoy the blad, what an amazing tool. Being a Canon digital only, untill I had a play with a blad.
That was it, I had to have one, so when hunting, and found some, 500C/M with an 80mm CF and a 503CW with 60 and 180mm CF for myself. I did also buy a 500EL but it is just sitting on the counter and looking pretty with a WLF.
I really like the look and feel for the images, and the large view finder is just amazing. I have even managed to get my 9 year old daughter interested in photography - now she wants a blad too :-)
As for the chrome or C lenses vs CF (black lenses), the CF lenses have coating to minimize flare AFAIK and there is a different flash connector. If you are really interested then get a the Hasselblad book by Ernest ...... forgot the name, but his books has almost everything you need to know about the blad's however, unless you are also looking at the H-series, then don't buy the latest which I think is version 5, but get an older one.
And yes, get the camera key, they are about 15-20 dollars on eBay, to unjam your camera, cos you are most likely to jam it, in the first few weeks when playing around :-) ehhh, speaking from experience!!
Next is of course - you guessed it, a Digital back!!! (yes, one (I) can always dream!)
Good luck
Henrik