I looked into this extensively for the last two summers. The Iridium phone service is best by far--don't even consider the Globalstar servcie.
The Motorola 9555, with the package which includes an external antenna, extra battery and 12 volt as well as 120 volt charger. These are relitatively expensive, and the air time is also expensive, in comparison to data or cell phone plans. If you want to buy there are a couple of places which sell used phones which are sold by military returning from deployment, compete with some un-used minutes.
Even though we had a relitative who we knew could be critical, we decided that other communciation would be adequate. In BC at least up the Broughtson, we found that almost every little marina had wireless internt, and most were free, or a minimal charge. Cell phone coverage was also fairly good. In Alaska the cell phone coverage was really fairly good, and there were less internet connections. We were able to make contact at least every other day.
If you worry about your own safety--then get an Personal Locator Beacon--EPIRB--they are about $300 complete with internal GPS and will get help very quickly in most cases. If you want others to know where you are, then get SPOT, with its tracking ability and limited messages, it can assure folks you are OK. Also VHF radio is fairly good up there. When we were in the Inland Passage in the Cal 46 we participated in several Maydays, via the lighthouses relaying the distress calls. I also had both Canadian and US coast guard folks tell use that in the case of emergencies from home that they could relay messages, especially if they knew approximately where you are.
For most of our long distance cruising, I used Ham radio. This gave me daily contact via phone patches or relays. The cost is less than a satellite phone by far, Ham can do slow text messages (Winlink) or Marine SSE Sail mail. There are also several good nets for information in the PNW. You can find a good older ham set for $500, and a tuner plus antenna a couple of hundred more. Morse code is no longer necessary for a "general" license--which allows voice frequencies.
Unless you are going to be way out of the beaten boating track--and it is hard to think where that may be, I think that the Satellite phone is a very expenisve and probably not necessary item.
Enjoy some of the best cruising in the world.