There is Quicken for Mac which, until recently, had parity of feature with Quicken for the Dark Side. The current version "Essentials for Mac" was poorly received as it lacked much of what people need in financial software. You can check the Intuit site to see if they have relented and restored the missing features--there was quite an uproar over it.
There are many other money packages that allow online banking. If you google "mac financial software" you will see many listed. As only you can know what features you require, that's about as far I can go.
BTW, if your iMac is running OS 10.6.7, you have a newer model with an Intel processor, whereas this forum is for older iMacs. Consider putting new posts--especially any that deal with hardware issues--in the Intel iMac forums here: