Thanks to both of you, this is exactly the kind of experiences and input I wanted to read about. And yes it is a pretty big project on the scale of bunny breedables, though it would feel and work closer to what A&D and Bloodlines are. However like any new project in SL, there's still a chance it wont work/pick up.
A follow up question would be could I get away at first with something like David mentioned, a work for hire, where I would own the rights by default, of course with a basic legal agreement that lays out what the job is for. Could I later look into proper IP rights, registering my work, ideas, etc.
It has the potential for a lot of growth but would definitely require a lot of database/scripting work. Right now it is closer to a hobby project but the more I work on it, the closer it is to something that would be quite commercial.