I would never look at the Scubapro brand for cold water diving. They are experts in piston regulators, so why anyone would buy the MK17 when for the same amount of money you can purchase a diaphragm that is just as good if not better from a company that specializes in diaphragm regulators is beyond me.
Now, you don't have to spend insane amounts of money on regulators, and there are lots of other questions you need to answer before we can even begin to make a recommendation.
You want the actual gold standard for true cold water diving? You have two options, Poseidon, then Apeks. That's it. There are drawbacks to both, and the main one for Apeks is regulators like the Dive Rite XT are half the price, and perform just as well.
Now the questions.
Do you now or do you plan to own your own tanks?
How much travel to tropical destinations do you anticipate?
How religious are you with proper gear rinsing before the regs are allowed to dry out?
Do you see yourself diving doubles, sidemount, or with a pony bottle in the future? Pony bottles and doubles are not uncommon in the PNW due to the depths.
Do you have any interest in servicing your own equipment to save insane amounts of money over the course of your diving career?
Answer those first, then we can actually give you a better recommendation.
Even without those questions answered, the set listed below is the best bang for buck option. Cold water compatible, comes with all of the gear you need for diving single tank with a pony bottle, sidemount, or backmount *just call and get the right size hoses*, at $700 is a great deal, has good support globally for service, but can also be easily serviced at home.
Cave Adventurers - Dive Rite XT Sidemount Regulator Package - Marianna, Florida USA - Never Undersold!