@Phil ******
you don't have enough time left on this trip to apply for first the 90 day Non-O and then the year extension, you would have needed to get after it right after you landed on that tourist visa and got stamped in for 60 days.
The best advice I can give is take the one 30 day regular extension you can get for 1900 baht and NEXT TIME either get a 90 day non-O visa from the thai consulate in your country before you come here OR get here and immediately go apply for the in country 90 day Non-O for 2000baht (by showing you have 800K baht in a thai bank account transferred in from abroad) then once you get that wait the 2 months so the funds can season and apply for the year extension for 1900baht.
This trip there's just not enough time for you to pull it off with an april departure date