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.
So taking your proposed 2k a month less rent that leaves you $1340 which is around $45/day, let's say,1500 baht/day, for everything else. Good luck keeping to that budget with a gf tagging along.
You must continue to meet the requirements for the current extension for the full year. The 800k must remain in your account for three months after your extension is approved and must not drop below 400k at any time during the year. It then needs to be back to 800k two months before applying for your next extension. If you failed to do this then you have not met the conditions on which your current extension was approved and therefore won't be able to use monthly transfers.