If I were you, I would go for the in-class training in Bangkok followed by the 5 month (or 10) teaching placement. The in-class training is far more valuable then an online-training and takes only 2 or 3 weeks, compared to 120 hours online (approx. 40-50 days).
Take care that AFTER the teaching placement, you receive a TEFL certificate which mentions: 120 hours TEFL training and that there is NO online TEFL mentioned. An online TEFL certificate is basically worthless without proper teaching experience and that is what the 5 or 10 months are for.
Internationally recognized? Most if not all TEFL, TESOL or CELTA institutes are internationally recognized. Just a few are accredited by the World TEFL Organization. (see: Guardian.co.uk)
Most important for TEFL/TESOL teachers is:
- having at least a Bachelor Degree (if possible in English teaching or education in general)
- a TEFL/TESOL/CLETA certificate (not only online)
- enough experience to be confident
- being a native (or near-native) speaker of English