a few years of 6 months Thailand 6 months UK then 12 months Thailand using back to back METVs with border runs. It is hassle but can be done, Elite will be painless but cost more so up to you. I also considered Elite but i was 45 not 41 so nearer 50 so decided on alternative route for a few years
Are you sure you want to stay in Thailand for 20+ years? some people get bored or crash and burn. The 20 year 1m Elite avoids a lot of pain, I'd go for that at 41, if nearer 50 I wouldn't bother