Sterio problem ( I think)

[Bushbasher]

The other day the sterio in the wagon suddenly blew the fuse out of the blue and now there is a short in the circuit somewhere that I can't seem to find easily. I have a few questions before I go climbing under the dash and start to try and trace it;
- What else is on the stereo circuit that might be causing the short?
- Is it likely to just be the head unit itself?
- Where are the most likely spots that a short can manifest itself that'd be the first places to check?
_ If it is the head unit itself, what would be a good reliable and cost effective aftermarket replacement that will be easiest to fit and hopefully plug straight in without needing rewiring?

Any help would be most gratefully appreciated as it would save me a heap of time and agrivation of possably pulling the dash apart for nothing.

Cheers
Bushbasher