stoiclown:Have you considered an Apeks XTX 50 with a DS4 first stage and a DIN valve. I bring up the DIN valve because it sounds like you dive in cold water and might use steel tanks or have access to HP steel tanks. My second reason for bringing up a Din valve is the ease of adding a DIN to Yoke adapter, which gives you the ability to use both setups.
I also second the DS4 with XTX50/XTX50 second and octo. Like DaAquamaster I too am pretty annoyed at the marketing and service of SP.
The Aqualung LX was my first reg however, the DS4 or any of the apeks are cold water capable, service real easy, parts are easy to find and almost never go out of stock and the fact that any of the Apeks regs have gone way deeper and longer than I probably ever will.
Apeks... nuff said
SangP