Having traveled back and forth to Thailand over the last 14 years I soon came to realise that if you would just send the funds you intend to spend in Thailand
Flights ,Accommodation, Sustenance et al ,immigration would be happy for you to not come at all
Best advice is to get a 90 single entry Visa in your home Country and then use 60 day Visa on entry by flying out if you need longer
You also need to be aware if you stay longer than 179 days there may be Income Tax issues to deal with