The Infocus is brighter, so if you have ambient light in the room or can't get a perfect blackout for viewing, that might be the better choice. I am using an HTPC as well, but if you're relying on the internal deinterlacer, the Faroudja is hard to beat as Junkster has mentioned, so that's another plus for the 7205 IMHO.
Both have similar contrast ratings out of the box (2200:1 for 7205, 2300:1 for H77, which I measured myself), though I have read that to get true calibrated D65 from the 7205, it can only give 1000:1 contrast ratio:
http://www.avsforum.com/avs-vb/showthread.php?postid=5091346#post5091346
http://www.hometheatermag.com/frontprojectors/704dlp/index3.html
I've achieved 2600:1 @D65 with the use of colour correction filters, and as I can see the difference in dark area detail over my HT1000 which has 2000:1 (calibrated) CR, I would choose the H77, but that's because I was able to calibrate the machine myself.
I would reccomend a viewing though - the H77 can have some issues with panning on some machines, and I think this is due to 8 segments which reduce the switching time for the DMD due to smaller colour segments. I can't say that I've noticed it (yet anyway), but for those that do it can be very distracting.
I wouldn't like to say which is best, as both have their good and bad points and out of the box are very similar it would seem. The Marantz has always had good reviews, and that sounds like the best choice if the price is right, but the only way to know what is best *for you* is to try and demo them all.
Gary.