HDMI is rumored to provide better HD picture than component cables, but I've never really noticed a difference. I have both, so it doesn't really matter for me. You do not NEED an HDMI port on your TV for the PS3, but it would be a good thing to have, especially if the TV goes up to 1080p resolution. Although component cables can transmit full HD resolution, I believe that I've read in the past that the picture would be worse than HDMI, this time noticeably.
About HDMI 1.3, you only need that if you have a specific type of surround sound system. I do not remember the exact details, but unless you see that your surround sound system supports HDMI 1.3, then you do not need it. I believe that it doesn't really matter if your TV has HDMI 1.2 or 1.3 ports because it won't be sending surround sound signal through its speakers anyway.
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