Well, dice is up to you. You can leave it up to the players (what I usually do, because it's slightly lower maintenance), roll everything yourself, or use an independant roller. I don't know of any really good ones. I use Invisible Castle for D&D rolling, but I'm not aware of a similar one for SR-related-endeavors.
Running a PBP game takes... patience. You don't even need a complete story, just a concept and a few details to get started. You might have a complete idea, but it's going to take a few months, if not a year or so to get through it. Shorter is better.
We have an area in these forums for PBP games. It's down at the bottom, under "Welcome to the Shadows" Just start a thread under any name, and designate it as 'your thread.' It also helps to cut down on in-thread chatter to have a second thread designated for OOC (out-of-character) stuff.
The player cap isn't going to be a problem. A bunch of people on these threads are interested in games, but not everyone is able to make the time to visit the site every day and keep up on the thread. Having a small game for one, two, or three players would probably work best. Also, people usually drop out early on in the game, so seperating players at the beginning works the best. At least, that's been my experience.
Any other questions?
-kv
