Knee Knocker A/C

Has anybody found an under dash evaporator unit that fits early As decently, and minimizes the "knee knockin'" issue? I've test fitted several different units, both aftermarket and Mopar dealer-installed ones in my '66 Dart wagon and have yet to find one that I'm reasonably happy with... they're either too wide and restrict legroom too much, and/or too deep and protrude too far out from the dash. Would prefer an air only unit, but I'm beginning to think a combination air/heat unit is the only way I'll gain the necessary legroom, after removing the factory heater box.
0% chance of replacing the firewall for a factory A/C setup- just not happening.
Any suggestions? Pictures of what has worked for you would be nice, too if possible...
Thanks in advance!

There are all kinds on EBay.

New Universal Underdash AC Evaporator 12V Heat & Cool Black | eBay