Greg that budget will be blown quickly with Paradigm Sigs.... Unless he goes with S4's for front, C3 center, and S2's and ADP's for surrounds...
That would be a killer setup, and in my eyes rivaled by few....
I was at 5-6K with a full Paradigm Studio setup, not including anything else...
but my room is 3 times the size of his, so I went with large speakers...
Lots of good suggestions here...
I am partial to the Studios, and think they are a great speaker.... You don't really need large speakers with that small room.... Mazer makes some great suggestions... but deffinately let your ears be your guide, go sample a bunch of speakers to see what you like... remember that you are very used to the Klipsch sound which for some is quite bright and revealing...
Good Luck