OK let me begin by saying, just by the terms you are using, you know more about this than I do, I just joined this forum, as I'm very new to Xbox 360 or any video game capture, but like everything I'm thinking of buying, I do my research, and I noticed no one had replied, so I thought I'd try and point you in the right direction
This a bonafide link, I wouldn't even know how to spam someone, lol.
Blackmagick Intensity Pro
and so is this one below
HD PVR
now there is a bunch of options for using your HDMI, funny thing is you probably knew all this, but hey, I like to try and help, plus thats very similar to what I'm asking about, well anyway, I hope you can find what you are looking for, take care