I've looked at both of these and done one of them.
I had a perfectly good CC system in a CDX I scrapped, but looking at transplanting it into my CD I am sure would have been a dash off job. Having had CC and A/C I can honestly say that I prefer the A/C. Not just in Vx but in many cars CC seems to have a mind of its own - in the Vx system you also only get 1 degree resolution.
You can fit xenons by using the "manual" levellers from your old headlights. Adding the auto levellers with sensors and ECU isn't a job for the faint hearted, lots of wiring to do. You should really also add headlight washers - not difficult. They key thing though is to ensure that you get a short length of cable with the xenons as there is an additional one not on standard headlights. These can be paralleled in, but really need to be spliced carefully as xenons carry very large inrush currents (I measured 18 amps) on startup and then gradually settle down to about 3.5 amps after a few mins. NOT a job for Scotchbloks or screw terminals, you will also need a good sized soldering iron and the heat will conduct away up the thick cable.
HTH ,,,,,,,,, Rob