Thanks for everyones' suggestions. Based on what I have read, and since the La Scalas are heavy (~125 lbs)and not internally braced,I think I will go with the under-speaker shelf support using eyebolts and (4) 3/8" stranded wire cables w/vinyl coating attached to (2) 1/2" threaded rods per speaker (this will allow tilt). The rods will go through the ceiling and attach to 2x8s straddling and screwed to the ceiling joists above my room.
I may sandwich the ceiling drywall with some oak for cosmetic purposes as well as to keep the drywall intact from speaker movement.
JBL has a technical bulletin "Basic principles for Suspending Loudspeaker Systems" which has good basic info. Go to:
http://www.jblpro.com/pub/technote/tn_v1n14.pdf
I'll let you know how things work out... now I just need to find the time.