Your options are basically this; you get a non-immigrant 'O' visa on the basis of marriage to a Thai in your own country, this can be either a single entry or a multiple entry. the single entry will give you 90 days, the multiple will give you a maximum of 450 days with hops out of Thailand to a neighbouring country every 90 days. To make your stay in Thailand as permanent as it can be in your situation you will have to apply for an extension to the non-immigrant 'O' visa when you are in Thailand - there is an immigration office in Hua Hin where you can do this. To qualify for the extension you have to prove to the immigration officer that the marital income is at least 40,000 baht per month, and this can be your income, your wife's or a combination, and it can be money earned overseas (for example interest on a savings account in your country) as long as it is verified by your Embassy. It is normally advised to do this when you have a couple of months left on the validity of your visa (it says on it 'Valid until xx/xx/xxxx'). You will obviously have to produce original and copies of passport and relevant documents at immigration, plus the paperwork relevant to your financial standing. Finally this will cost the princely sum of 1900 baht. If successful you will have to report to the immigration office every 90 days until 1 year is up, when you apply again for the extension, going through the same process.
The only other option is to find a job in Thailand and get a work permit, but i will leave others to explain that as I have no knowledge of the process. Once you turn 50 you also have the option of a retirement extension, similar to the marriage one, but the financial requirements are much higher for some bizarre reason. However the retirement visa extension does also allow you to show a lump sum in a Thai bank as proof of sufficient funds, which i believe is currently 800,000 baht, and there is also a combination option with any income. Again i will let others more au fait with that explain it fully, plus by the time you are 50 it will undoubtedly have changed again!
There are plenty of threads on these subjects though, so i suggest you look in the Legal, Visa, Finances & Employment sub forum (which your post is in) to find out more. Incidentally your wife is wrong unless she has some very high powered connections in immigration!
