The AJA IO LA is your best choice. It’ll allow for Component in and out.
It will allow for uncompressed as well. A year or 2 down the roads you can add the Kona 2 (or what ever is out then) if you go HD.
I have the IO LA and I’m very happy w/ it.
I had the same prob. Received a new 2.7 and wanted OS 10.3 and had big problems and then no startup. Finally got the Disc drive open and reinstalled 10.4.
Your audio should play out the AJA IO LA. Your video and audio play out throught the firewire cable from the mac to the IO From the IO LA to your monitor, deck, mixer