I am doing the same in JAM...at this very point in time.
Initially I cut and welded the heater mounting brackets further up the firewall, so the heater will sit under the dash more, and not next to my feet

(which I hate in clubbies).
Then I decided to give it the flick, but was told it IS NEEDED for rego in NSW (the demister part anyway). So I am keeping it, but won't hook up the heater. It will serve as a fan to blow air onto my windscreen only. That means I don't need the slide heater control for it, as all I need is 1 switch to turn on/off.
I am mounting ALL my switches on my dash, then making a new face for the part in the dash where the switches used to be. In this face I will put a covered provision for a radio. I am not running a radio in JAM, but there is nothing wrong with planning ahead, in case I want one later.
FatMaserati, you have a good plan there! I will love to see your finished item!