[NiHaoMike]

The window units I'm looking at definitely won't have inverters. As nice as it would be, it most likely would be running for hours at a time every day and not on at all othertimes. A Danfoss Little Kim would be awesome just from an efficiency standpoint, but just finding one is a challenge...

If the condenser is the main difference and the compressors are basically the same, then there is little value starting with a more efficient unit since I'm going to replace that with a water cooled condenser. The existing condenser would become a second evaporator (with an ejector cycle) so the evaporator would then be sized to the point of diminishing returns. The fans would be replaced with variable speed ECM to allow fine control over the evaporator temperature for better dehumidification, so the efficiency of the existing fan motor is irrelevant. I probably won't use Cindy Wu technology for the fans since that excels at high airflow (great for cooling computers and other electronics) and I probably won't need that for this application. (I can always upgrade later...)

The main advantage I see going with a R410a compressor is that it would be working under less stress so it will last longer and allow for higher hot water temperatures if the need arises. (I plan to set the outlet water temperature to 140F for washing dishes. The actual condensing temperature would probably be lower since the inlet water is going to be on the order of 80F or so worst case.)