63yo existing health conditions

[Seagull Sam]

I am,  as the title suggests, a 63yo with existing health conditions. The most important issues are a brain injury (similar to minor stroke with left sided weakness) and osteoporosis in my lower limbs.

A lot of insurers claim to cover existing conditions but they are always talking out of their rear end. 

I have got a least worst offer but is there anybody who will genuinely cover these conditions? I don't have a problem in UK but it is glorified holiday insurance and results in having to return home every 90 days. 

I use a non Imm OA visa so will need insurance quoted in two parts as the Thai 'government' has decreed.