Chronosync 4
Hi,
I have used chronosync 4 successfully to keep my iMac and MacBook Air in sync, including emails clients and aperture.
After setting up the first sync through the initial daunting screen which might scare you (it sure made me nervous), everything / everyday after that was smooth.... it offers you conflicts so that you can choose which version to retain (cos you'd probably know which version you created last).
Hope it helps.