The Scubapro Mk 2 and Mk 17 first stages are very reliable in cold water, and in fact the Mk 17 is in my opinion and experience the most relaible cold water first stage currently available from any manufacturer.
Both are compact and are, for a chrome plated first stage, fairly lightweight. You can get either of them in DIN or Yoke versions. If you go DIN, you can use a DIN to Yoke adapter in locations that do not offer DIN valves.
I am not a big fan of the Mk 25 first stage in cold water as they have been known to have issues with freezing up in water colder than 40-45 degrees F. The Mk 25 is however available in lightweight titanium (MK 25T) and stainless steel/aluminum (Mk 25SA) versions. The Mk 25SA is not too bad price wise, but the MK 25T is well into the conspicous consumption category.
In terms of high performance second stages, I like the both G250 and X650 second stages in cold water, but am not a large fan of the S600 as they tend to freeflow slightly in very cold water. For lower performance second stages any of the R190/R290/R295/R390 family work quite well.
The Aqualung Legend is another good choice in it's adjustable LX models. It is available with a cold water kit and while it is not my favorite regulator it is none the less a good all-round high performance regulator.
Hopefully you will have either a Scubapro or Aqualung dealer in your area. Both have very wide ranging dealer networks so parts and service support is easy to find and both companies have a history of providing long term parts and service support for their discontinued models, so the reg you buy today will still be useable and serviceable in 5, 10 or 20 years. Scubapro in fact has a policy of making improvements in new model retrofittbale into older models whenever possible, and this can keep your reg performing on par with newer models for as long as you own it.
Both are compact and are, for a chrome plated first stage, fairly lightweight. You can get either of them in DIN or Yoke versions. If you go DIN, you can use a DIN to Yoke adapter in locations that do not offer DIN valves.
I am not a big fan of the Mk 25 first stage in cold water as they have been known to have issues with freezing up in water colder than 40-45 degrees F. The Mk 25 is however available in lightweight titanium (MK 25T) and stainless steel/aluminum (Mk 25SA) versions. The Mk 25SA is not too bad price wise, but the MK 25T is well into the conspicous consumption category.
In terms of high performance second stages, I like the both G250 and X650 second stages in cold water, but am not a large fan of the S600 as they tend to freeflow slightly in very cold water. For lower performance second stages any of the R190/R290/R295/R390 family work quite well.
The Aqualung Legend is another good choice in it's adjustable LX models. It is available with a cold water kit and while it is not my favorite regulator it is none the less a good all-round high performance regulator.
Hopefully you will have either a Scubapro or Aqualung dealer in your area. Both have very wide ranging dealer networks so parts and service support is easy to find and both companies have a history of providing long term parts and service support for their discontinued models, so the reg you buy today will still be useable and serviceable in 5, 10 or 20 years. Scubapro in fact has a policy of making improvements in new model retrofittbale into older models whenever possible, and this can keep your reg performing on par with newer models for as long as you own it.