abecedarianmind... have you ever performed a Seance?
How about attending both, real ones as well as those rigged to the hilt by other magicians?
95% of the magicians that attempt to set up a Seance try to do too much and rely more than need be, on gaffs and gimmicks. If however, you are after a Disney approved style Seance then maybe Manifestations would be a decent guideline... though I've not seen the BOO Book, I'm familiar with what Christian can deliver e.g. it's a great source along with the various Borodin books...
Final Curtain having some very cool Seance/Haunted Routines.
In my experience and that of many I've spoken with over the years that specialize in this sort of work, it takes a great deal of time to properly research and develop this kind of attraction. If however, you own the Victorian building you've mentioned, you may want to look at (given the size) creating a Mystery B&B that works in tandem with your neighbor i.e. they supply your food & bar, you supply the facility and muse. I have a huge chunk of my PSYCHIC TECHNOLOGIES manual dedicated to this sort of thing but would discourage you from taking short-cuts.
I do highly recommend that you get Paul Bell's booklet on doing Seance work "for real". You will also want to brush up on your Q&A work (Jon Riggs has several treatments on this topic that you'll find of great value. There is also the new Bob Cassidy compendium); one particular routine I've used many times in Seance settings is Nelson's VISIONS OF TOMORROW; it's a crystal gazing bit that's quite cool in that you hand the slip you are divining straight back to the guest you are Reading... it fools magicians (and I've seen it used in Spiritualists churches, so it must be solid

)
In regards to your table let me give you some unsolicited advice... DON'T DO IT!
A table that large is a royal pain to deal with and chances are quite likely, you'll be coughing up a huge sum of cash for something you can't readily use anywhere down the road should you have to close the act. Secondly, if you have the unit too gimmicked you run a huge risk of having your tricks & whistles discovered by nosy patrons (check out my pm however)
Just a few things to contemplate
