Does any one know if there are any good custom bike shops in BKK that specialize in choppers and bobbers?

There's one in RCA but I think its completely for Harleys but the owner is real nice and if they don't have what you want I'm sure he'll point you in the right direction

Cool cheers mate

The place in RCA is 8080 Cafe, it's located in block D of RCA which is your main block just down from Route/Slim/Flex.

Take a look at "mee classic" shop in Khorat. You can find them on Facebook or just google them. They do some sweet builds from choppers to bobbers to cafe racers.

8080 is a good place to make some contacts & have some of your questions answered.