I always thought that just doing even a basic eq "clone" client was probably rather too ambitious for a very small of people working part time... I would worry that you've expanded the scope a lot now, and you'll have to do a lot of server work and create all new content too.
While I certainyl wish you every sucess with this, I think you'll still be working on it in a year, assuming you can keep a focus for that long. I think a "tech demo" is easy but making a finished game is a lot harder.
Have you thought about using an existing rendering engine like
www.ogre3d.org ? It might reduce the scope of the work to something a bit more manageable, and you'd have the benefit of an engine that's probably had a lot more work put in than you'd have time to do.