I just sent a set of HOG's to Australia along with service kits. There is also a set in Okinawa unless the guy has shipped out. Haven't heard from him in a while. If you are techincally minded and skilled, reg service is not that difficult. What can be difficult with some brands, even major ones, is getting parts to do them yourself along with support from the mfg. HOG offers that. There are a few pre requisites for the training course but they are not outrageous and links to the schematics can be found here on the board. They are one of the brands that recommends a two year rebuild interval as opposed to one. There is a recommended annual inspection but it is recommended. When I do one I adjust the IP and cracking pressures if necessary, replace the HP spool orings, give it a good cleaning that does not require a complete tear down of the stages, and replace any worn o-rings.
As for sending away for annual service the biggest investment there is time. Since you're in the military as most of my overseas customers are international UPS is waste of money. Shipping to an APO/FPO is the same as shipping across town and it can be tracked (to Okinawa about $15 plus 8 for insurance). The reg I sent to Australia took 6 days to get there and an additional day going thru customs. Not bad as that was not a military member.
I'd be happy to answer any questions you have about them and how to get it to you.
Regardless of what reg you go for there are a few things I consider essential for my own personal satisifaction. First I like an adjustable second stage. Second I prefer a first stage that is balanced and sealed against the environment. Commonly called by some a cold water reg, the features that make it suitable for cold water also make it great for diving in saltwater, silty or sandy conditions, or those with lots of dense vegetation, algae, duckweed, etc. Also makes them easier to rinse and take care of. I also want regs that I don't need tools to take the second stage cover off. Makes it easier for minor field repairs like a folded exhaust diapghragm or one that's gotten something in it.
I like bigger second stages since I often dive with heavy gloves and they just feel more secure. I like regs that I can service myself and get parts for. You can get parts for many regs but some you have know the secret handshake, password, take a vow of secrecy, and swear that you did not get them from who you got them from. Bull. I like regs I can go to a dealer and say hey, I need second stage and first stage kits and they say ok and sell them to me.
I also want regs that I can afford and are worth what they cost. I do not want to pay for a name, flashy advertising, gimmicks, or cosmetics. I don't care about gold trim. I want a reg that works, is a proven design, and is reliable. I want good support from the mfg and be able to talk to someone there when I have a problem. Not get told go to your nearest LDS and ask them. Ever think that the reason I'm calling the mfg is cause the LDs will not or cannot address my issue? Or because they have shown that they cannot be trusted, talked me into something I don't need, could not really afford, or perhaps I just don't like them? It's why I bought HOG's long before I started selling them.