I do similar work
I looked at MarketCircle's DayLite, and yeah, its neat, lacks the actual database part that you are probably looking for, so I went with Bento, because Address Book and iCal already do a big part of DayLite, IMO. There is no good way to get DayLite to act like a database and less like a fancy PIM, so I did not buy it.
This has always been a sticking point with the Mac (user for 10 years now) and though daylight is the "touted" application for this, having been a former salesforce.com user, I have always found it a little awkward to use. You will have to think out how you want to set up Bento, but it will do what you want better, and it is cheaper. On, the other hand, if you MUST have a shared, networked solution, then Bento will not work for this, otherwise it will.