Thanks. 4 co's and 6 extensions is most likely the max, but we have all made that mistake before. Intercom would be nice but not if it is going to drive the price out of site. Do any of these KSU's support conference? I will most likely set up 3 extensions w/ short runs (~25 ft)for testing and if I am happy I will measure and snake the house w/ long runs. It will certainly be a cool look for the house. Just wondering cost so I can budget.