well if you want to get one from scubatoys and i know money is a issue
http://scubatoys.com/store/detail.asp?PRODUCT_ID=V16Proton
like i said they make a good reg..
me im pickey about my gear...
ez to work on so if theres a problem you can fix it yourself.. also i always do all my own service.. so get one that you can service ez without all kinds of crazy special tools..
markfm suggested sherwood..
there a god reg.. ez to service.. excellent reputation in cold water...
me. i use scubapro.
i see a MK2 R190 on scubatoys for short money.. thats not bad..
the Mk 2 is a unbalanced piston reg...
i have one and never had a problem with it...
MK 16 is my recomendation (they stoped making them but alot of dealers still have stock) diaphram reg (all diaphram regs are balanced by default due to the design) and i have dove with my MK 16 for several winters
little more to the service, but still not hard.
my primary regs are scubapro MK20- and MK 25 some people have had issues from time to time with the 25 but i havent.... it probaly is more of a issue of proper service but .. in general diaphram regs have a beter record in cold water than piston
now... if moneys not a issue...
hands down.. jetstreams for cold water.... i think i might get a set after the new year. i dunno yet tho.......
i wanna replace my deco regs, and ill use poseidon X-streams for that..
so there...