I emailed them a few weeks ago. I guess they're working on a new model, but no word on release date.
If we are talking about SpectraPure, we all it happens soon. There are no complaints on the web about their LMIII and I hope the V.4 is only going to be better. These are capable of changing a lot of water per day if needed in certain configurations and can pump up and over anything you throw at it.
Used LMIII are impossible to find used because unless somebody is getting out of the hobby everyone is just using them. I've posted in WTB sections here and on RC, no bites except one dude that had one from 2009 - didnt really want to risk it especially when people ask nearly retail prices for these.