There's a lot of different brands of HD-PVRs.
The ones I know of are:
Haupaugge HD-PVR / HD-PVR Gaming Edition
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Black-Magic Intensity
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AVerMedia Game Capture HD
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Elgato Game Capture HD
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The one I prefer is the Black-Magic Intensity, but that's just opinion. You can go with whatever you want. Do your research; use Google, YouTube, etc.
And for a mic to use for commentating, for beginners, I'd go with the Blue Snowball Microphone
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If you want, you could get a Blue Yeti Microphone, but I'd only suggest getting this one once you're partnered
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