I like coding somewhere where I don't have anything I have to do except code. A hotel/motel with wifi is a great place because it has very little distractions (people, chores,...) and it's extremely confortable. Having a king size bed or a couch just for yourself and your laptop can help your concentration. Unfortunately, this costs money, so this isn't a good solution for everyday coding.
I've been running Zenwalk on my EEE 901 for months now and haven't had much trouble. I wouldn't suggest it for people who like everything working out of the box, since I had to install both wifi and eth drivers on my own, so you don't have any connectivity in the beginning.
You should definitely try the OS you're considering on a virtual machine first, just to be sure that you like it. Also, whichever distro you choose, you'll have to do your homework first;)
why not use the users then? have them help each other:) have tech support that can help you with basic stuff and have users answering each other's questions on the forums/chat. do you happen to know what are actual expenses for small ISPs these days? what kind of personnel, equipment and software do they need?