Having done this type of consulting myself, I could never work around the maintenance issue.
You likely setup the entire system so if something goes wrong, whether its you're fault or not, you're on the line. It's all about reputation. And if you tarnish that by leaving a paid client behind when their server catches on fire, it will be remembered negatively.
It's hard to do this type of contract work continuously. You build up a portfolio of apps that you have to maintain. Most of the time you're clients are out of cash.
Equity is great but it doesn't put food on the table today. On the other hand it puts you in contact with some really great ideas and you get to play startup founder several times and you gain enormous perspective on what works and what doesn't.