You can buy the Brompton Clones in many bike shops in Bangkok..The LA franchise bike shops seems to sell them..You can find them in Worachak Road also not far from Khao San Road area..You can also get them delivered to your door if you look on Lazada.co.th..
I haven't ridden one but they use the same hub gear as Brompton and some of their design features are useful..ie..adjustable bar height....built in carrier ..
I have seen other Brompton clones at the AIM bike shop in Nonthaburi..up the river in the north of BKK..