We've been using PHP Live Helper for about a year and a half now, this is a great program. You pay a one off fee and thats it unless you want to have updates after the first year.
The program is sleek, very customizable and most importantly it works! We've tried lot's of other live helper products but this rivals any others and surpasses all the ones I have used personally.
The latest version adds even more facilities, I can't recommend PHP Live Helper enough,
Worth every penny!