If you are not back before the last date of your permission to stay date, it has absolute no value to buy a re-entry permit as that will be valid until the same date.
Look up the requirements for a new Non Immigrant O visa based on being married to a Thai National, bring all needed copies on the trip and apply for a new visa while abroad.
2 months visa better known as a Single Entry Tourist Visa which gives 60 days on entry.
You can get once a 30 day Extension of Stay based on tourism, than a 60 day Extension of Stay based on visiting family and you might convert your visa into the Non Immigrant O visa based on being married, but for that you need 400.000 Thb on a Thai bank account and some other copies of legal documents.
If you are using income made in Thailand, it will be copies of work permit and the last 3 months of paying income tax and sso for you and for the Thai employees needed to get the work permit.
Your minimum Thai wages must be 40.000 thb a month.
I have no idea where in Thailand the OP is going to live, but I know for sure that he can go after 45 days, they will inform him to make all needed copies and let him apply or inform him he has to wait a few more days and make an appointment to get thins done on the easy way.