You know, the answer may be not that short as you may expect as the topic is not that easy and flexible. I do not consider it as the best option, but maybe you should try to contact people who really perfect in such tasks? I've used http://www.christian-paul.net , it's easy and consumes not that much time. Frankly speaking, this topic is one of the hardest that i've seen last days.
I have a company that sells different fashion stylish cloths, its like an online store and I would recommend to live chat services as compared to telephone services! Just a simple way to outsource live chat support expert and start to giving live chat support to your visitor's or clients. This is much better way to provide your best client service.