I did see them while looking for the same setup as in mine, only thing with that is its not very expandable.
The one in mine has been wired such that the first fuse supply's everything the second fuse protects the parking module if the relay should fail and the others are consumers.
I like the idea of remote starting heaters
You seen these Ray?
http://www.autoelectricsupplies.co.u...01/category/37