I know this topic has been beaten to death, and I have done numerous searches, but I am still not positive what I need for a 24v - 12v converter. In my 87 BJ 73, I need to run my new stereo, which includes a sub box and a 300w 2 channel amp. I also would like to run my CB radio. I am looking at the ICT 20 amp converter from Huttons, here in Calgary. So, bottom line - new cd player, 300w amp, and CB radio. What do I need for amps in a converter? Please help!! 