Gregg, were the PD pumps you tried Proconn? Shouldn't be noisy and you can always throw a towel on it .
I checked Proconn website and it looks like they're not pushing the product for HVAC circulators anymore.
Who uses a temporary adjustable speed pump, flowmeter & pressure gage to determine the head curve of the system before selecting a circulator? Instead everybody selects by over estimating the head. So a PD pump seems like a sure way to get the correct flow rate.