Greetings,
There are several private groups that you need to join on facebook, here's one of the most popular ones
expats and locals living in siem reap
facebook.com/groups/siemreap/
if you go on facebook and do a search on siem reap to see how many different groups there are and join them, then you can ask questions about your needs. this one is not used as much in siem rep by those who live there. I live in sihanoukville and recently moved from siem reap.
my general advice is to first make a trip here to visit siem reap to assess your needs and see if it would work out. Also make a trip to sihanoukville and PP to compare which place is better. Most major medical care is done in Thailand but siem reap does have better doctors over sihanoukville. Not sure about PP but I'm guessing it should have better facilities over both places.
it is not the same all over cambodia, each has pros and cons about them. transportation is a problem here too. if you don't have personal transportation, getting around to see places and do things can be very expensive over time. driving in cambodia overall is 'high risk' too as well as the liabilities against you. if you can afford a car and driver here, living here in retirement can be a wonderful experience. otherwise, if you can't get around a lot, it can get to be very boring and mundane over time.
also speaking khmer, it's a hard language to learn but you can get away speaking english in siem reap but keep in mind the prices you pay will be higher where they can charge you more or if you don't know what those who know pay. outside of siem reap, its hard to get around without knowing how to speak khmer. one of the main reasons most people suggest finding a girlfriend who can understand english.
i did a years worth of researching before coming here and still there was a lot that I found out was wrong info. Had I took a trip here first to do an assessment, I would have known better what I needed to bring with me and have a better idea of the cost of living here and what to expect.
my personal assessment to live here in comfort and to stay active to see and do things here is that you need a car and hire a driver/personal assistant and live in housekeeper/cook which means having the capital to lease a place, buy a car, etc and have a retirement income of at least 3k a month to maintain it. To have a girlfriend, you may need more. that would guarantee you living a life like a 'king' and be able to afford to see all the wonders and beauty cambodia has to offer. i'm from america and you can't live like that for that kind of money there, i'm pretty sure it's the same in your country as well. most people who come here expects to pay less but it's not true. you can live more cheaply here but the quality of life is not as good as I stated. if you don't have solid khmer contacts of people that you can trust and know what's going on here, you are at a disadvantage. i had to learn the hard way and still paying for it here in sihanoukville too. people are different here from siem reap also.
so it can be a wonderful life of retirement here or difficult and disheartening. it depends on your wants and desires and be able to fulfill them here. having money can attain that here cheaper than where you live now, you just have to have enough of it to do it.
good luck and hope you have a good retirement life here.
hiram hiramoto