I dunno if its such a good idea, for the first time.

Maybe youd want it to be memorable and special - to an escort, youd be just another client.

Try flirting lightly around a bit more with the ladies at work and who you interact with and you would notice some becoming more receptive.
Or perhaps try placing an ad on Locanto/Cumtree etc, saying that you would like to experience your first bj - im not sure what the response rate is on there - but it might appeal to someone (in a similar situation), who you can build some chemistry with at first, before doing it.

Reason i advise you this way, is that lots of girls (esp Umhlanga) are scam artists who will make you first experience a nasty one.