The 5500 shifter is 9 speed, 9 clicks not more.
Your Front and Rear deraileur if a 5600 series are 10 speed and can work with 9 speed also.
So.... That's all she wrote
Or,
get New 10 speed shifters.
Nashbar has Ultegra 10 speed triple shifters for $149 that can work on your double
http://www.nashbar.com/profile.cfm?c...s%20%2D%20Road
You will still a new chain and a 10 speed cassette.
I would save your bucks and when you need, get a new compact crankset.
Rob