Riva:
I'm sure I have seen wire like this in Pantip Plaza but also try
http://www.wt.co.th
http://www.mynpe.com/
I think RS also have a Thai branch.
Interesting, WT is actually quite near to me - I will have to pay them a visit.
I bought my insulated wire from NPE, but their web site is a problem since I cannot read Thai.
I might have to go back the shop to have a look.
Last time I went not a single person spoke English and it was a real pain trying to communicate with them.
I already checked the RS web site - they don't seem to have uninsulated wire.