Intellisync has some pretty nice filters for synching only certain types of information. Can sync to more than one machine. There is a bunch of other features that exist too but I dont use. I've never used Cadenza so I dont know how that program compares to Intellisync. Intellisync offers a trial period of their software so you can see if it will do what you want it to.
Whatever the latest version is. Upon installation, Intellisync will ask you with what program you want to sync your PDA with (Outlook, Groupwise, Lotus, etc)