Victory conditions are surprisingly tricky. Some games have been won by a relatively small player suddenly teleporting SCs onto enough VPS to win in a single turn, which tends to make people feel the game was a bit pointless. I'm sure there's a way round this with a bit of thought though. In particular it should be possible to have an arbitrary victory condition since the server could parse the debug output and work things out itself - for example, you could say your average number of provinces over the last 5 turns must be at least n, or you must take and hold VPs for 5 turns.
I'd be very happy for you or anyone else to run a game on my server (although not quite now as I think I may have used up most of the demand for games for the moment). At present there's nothing to work out - just tell me the settings you want. When I get round to it I want to do a "Create Game" form on the website, but that will actually be quite a big job.
I really think victory conditions are quite silly. People should just call it quits when they have no hope of victory, and concede to whomever is in the lead. Or, if they want, they should hold out to the last man