I have done this on G4 with a new drive. I installed a new drive which was larger. Now on the hackintosh I would agree with the other fellow a Firewire connection. But before I do that I would clone the hackintosh drive just in case.
I did use migration for the G4 for app,settings mail, images. The new drive was clean install. Let us know how you fair. I too just finished my hack with a ASUS P5K board. Everything works and it is stable. I was able to transfer by network my address book . I really don't see that you should have any problem. Hope your enjoying your "new" computer.
Ciao,
Lou Cioccio