I've been searching for a small relay/fuse block and came across this. It's designed for motorcycles but can easily be used in a car. It has 6 circuts that can easily be configured for constant/ACC with a simple move of a fuse.

Any thoughts? I know it's a bit spendy, but I can't think of anything else that does what this does in a nice tidy little package.

http://www.fuzeblocks.com/index.php