sorry I made that giant blob response where I almost wanted to make a thread dedicated to the PD sources. So I was really looking for a solid one to get to try all this with, paralleling and stuff.
I am looking mostly at this as it is the cheapest and I found a nice video showing it off:
That would be using a battery or maybe 24V server psu so they would have identical V DC input.
does not seem to need contact with the case for cooling so I was thinking the easy way to make a compact dual PD would be to stack two of these in a case with some airflow.