Seems a bit back to front in that they went ahead and finalized their plans then asked if they're doing it right. Logic would suggest you do your research, come up with a proposed plan and then by all means run it by the group. I wish them luck.
You need to wait and check what the current requirements are when you are planning to move here. Nobody knows what will change or still be valid a few years down the track.
Wife and I actually did this yesterday. Took 30 minutes at the office to complete the process with two witnesses. Phone call this afternoon, go in tomorrow afternoon for ID photo and pick everything up...yellow book, kor ror 22 and card. Nakhon Phanom District Office.
Just use your wife's family residence...'I (wife's name and ID card number) will be sponsoring my husband (name) at my family's residence at (address) during his stay in Thailand (Include dates to align with 90 day visa). She signs, dates and includes her contact phone in US. Doesn't need to be in Thai, English is fine.