I 'think' you can still use Disclosure Scotland (yes even if you lived in England) to get a standard check done. I looked on the website, it says if you live outside the UK you have to do a postal thing instead of online.
I had to get one for my ed visa.... but from UK. I presume it would be from your home country.... I mean no point getting one from Thailand as they'd already be aware of any naughtiness no?