Transferring Contacts from Verizon t730 to Next i530. Help!

I carry two phones. Nextel i530 for walkie-talkie and free incoming;
Verizon t730 mostly for travel and roaming. I use iSync to keep
the t730 contacts up-to-date from my G-5 Mac, and couldn't live without
it. (To my sorrow, iSync won't work with iden phones--unless someone
knows something I don't??))

I need a way to transfer contacts (address book) from EITHER:

t730 (or my Mac G-5 address book) to i530.

I do have a PC available in addition to the Mac.

I don't want to type them in one-by-one. I have USB data cables for
both phones. I don't mind buying software, or going through several
steps to accomplish this.

TIA

John