Calendar and reminder system for windows XP

Hi guys. I’ve recently been implementing a basic GTD system. But I am stuck on a good calendar and reminder system for windows. Currently I use google calendar for appointments (and an email reminder). However, I would prefer the option of a popup reminder for some events (I check email only twice a day). Also, I haven’t figured out a good way to implement a tickler file. I have been creating all day events in goog calender. My ideal requirements would be :

• desktop application
• syncronization over 2 PCs.
• ntegrated with desktop email
• web access to my calendar (when traveling)

P.S. I am willing to pay!