Ok so I purchased a Cosair CX750M this morning.  It works with the paper clip trick and seems to be running 2 cubes just fine. However, the power wasn't the issue causing the poor performance.  It is nice to have 2 units on one power supply and not have to run it off a computer though.

My LAN was on the 172.0.16.* subnet and it appears that any stratum proxy hates this (even if the cubes are configured to point at the proper address and do connect - they will under perform).  

After moving to the 192.168.1.* subnet, the units are hashing at a combined 59-64 GH/S (in low mode).

So you must be on a 192.168.*.* at the very least . . .