Reliable agencies:
http://www.scortads.com/models.html
http://www.cumintj.com/
http://www.mexicolindobar.com/home/
http://foxystj.com/escorts/
http://queenstj.com/escorts/
http://www.adultbaja.com/
As far as the covered vs no covered action, it definitely varies. I've never had a CBJ from an escort or an independent, only from bar girls or streetwalkers. BBBJ is not guaranteed but is available from them. Make sure you ask about it before agreeing, and if she says no, move on. If you are looking for CFS, that's available from some girls (and usually for extra money), but never guaranteed. I've had some escorts or independent girls offer it up without being asked. Once I negotiated a girl down from her asking price, but promised a tip for good service. i was thinking CIM, or just DFK, but she offered up the BBFS. So it's possible.
I've tried many of those agencies. HMU for help if you need.
Edit: also, if you want independents check out these. Less reliable but often better value and service level.
https://mx.mileroticos.com/escorts/b...ornia/tijuana/
https://mx.sustitutas.com/escorts-putas-tijuana