TCIS/Thana City Interactive Map
This link is actually centered on where Thana City and TCIS are: the intersection of what is labelled as Bang Na - Bang Pa Kong (usually called Bang Na - Trat though) and Wat King Kaeo. You can see here that neither are technically in Bangkok (it's off to the NW).
This one is centered on aforementioned section of Sukhumvit (in tiny letters unless you zoom in).
Extremely helpful. From the front page, click search by location, then in Central Zone, click "Sukhumvit 1-71, Thonglor, Ekamai" and continue (there are other sections you could try too). On the next page, the fewer criteria you select (other than price range), the more apartments you'll see. A lot of places will get eliminated if you are too specific, and possibly not because they don't have what you specify, but because it's just not listed in their description. The people who run this site will search for an apartment to meet your needs as well, so long as its 15,000+ Baht per month. Otherwise you have to search for yourself. It's not super easy, but nice, reasonably priced apartments ARE out there.
Associated with Thai Apartments, for condos/townhouses/houses, rent/buy. More expensive. Same search services.
Brief cost of living in Bangkok breakdown
Mechum contributed these sections about living outside Thana
City and Related Sites based on three-years of working in TCIS until 2003.
He is currently teaching in Bolivia. You can also read the article about
Bangplee Market -
a traditional Thai market near Thana City - written by his brother, Newley
that was published by Worldhum.