As in the earlier answer from Michael, I like and use www.bioexsystems.com – reliable customer service, too. They also have all administration management software I need, nutritional blocks I can purchase additionally, and the softwares talk to each other. I’d highly recommend these guys. Good luck!
The physigraphe system is quite good. You can either buy the cd rom clip art or sign up for a monthly fee to use online services. There may be other options too. The images are standardized and simple. I also like the stick figure method but with physigraphe you save workouts and email them to clients as well as print them out.