Cam?

i wouldnt change the cam unless youve got new heads.

just throw some 1.7rockers on with your stock cam to get some more lift out of it

stock heads=stock cam. optional 1.7RR.

i belive its 1.7 times advertised Lift, instead of 1.6 times advertised lift....heh 1.7 will get u bit more cam without actually changin the cam

First, you should be looking at an intake manifold and gears.

Agreed. Intake and gears first (although I didn't....) A cam change will likely bring drivability issues you will HATE (poor idle, stalling), unless you've got some way to adjust for it (custom tune.) Besides the True Street guys are running in the 10's with a "Stock" cam.
To answer your question about the job, you can do it by pulling the upper intake, the valve covers, the front cover, remove the radiator, the distributor, rotate the AC condensor up out of the way, get the AFM lifter holder kit, and swap away. It's a full day for an experinced mechanic in a hurry, a weekend if done casually. If you don't get the AFM kit, then the lower intake has to come off as well, the lifter spider and all the lifers. Interstingly, the front dress (alternator, PSpump, etc) can stay on since they bolt to the head, not the timing coever like the older Mustangs.....
I wouldn't do it, yet....