I have found a script for that. If you have the right WRT54G or WAP54G it will all fit on there and there is enough power to process all of the information. The billing part just checks things and then it just sends it to paypal if the need to purchase more time or month and so on. I do how ever want to find a system for a computer to. Freeradius, I have looked at, but I haven't found a billing system for it. One of my biggest concerns is that if things don't go right, you can, "brick" the device. So, this is why I am looking so hard for a linux soultion that has everything in one package, not multiple.