NE1 replace their factory heater box with a street rod type

While looking through the Summit catalog I noticed they sell small heater/ defroster units.

http://www.summitracing.com/nv/parts/sum-991106/overview/

Has anybody ever swapped out their stock heater box assembly for one of this type? I'm building my Demon more into a pro touring/ road race car and looks like a good alternative to me.

I think Speedway Motors has a smaller box style unit that fits on top of the trans hump close to the firewall.