To clarify this.
It is correct that the Phase III dish will NOT receive any of the HD channels because it can't see the satellites in the 99 and 103 slots. There are a few HD channels on 110 and 119 but these are already mirrored on 99, and the 110/119 versions will be removed very soon, so you need a slimline dish in order to receive HD.
The comments and advice about DirecTV receivers/DVRs is generally correct. However only certain revisions of the H20-600 receiver were recalled. If you look under the receiver and there is no paper sticker showing the H20-600 is at ECO 2.0 then the receiver was subject to recall. I am not sure DirecTV is still processing the recall, there's a long thread on this at http://www.dbstalk.com/showthread.php?t=138686
The H20-600 is susceptible to overheating but that was NOT the reason for the recall. Still, I would be very careful about buying an H20-600 because many of them have been "cooked" and are already failing.
As far as owned vs lease is concerned, the advice in the post from mtrunz is very important. There are in fact many H20-600s out there that are owned, and some H20-100s - I have one of each and they are both "owned". Most of the HR2x DVRs out there are leased, but again there are a few "owned" units. I have three DVRs and two of them are "owned". If you see an HR21PRO out there, it is almost certainly "owned" since almost all were sold only to commercial establishments and there was no lease program. But as mtrunz has posted, it's very important to check the receiver/DVR numbers with DirecTV before you buy ANY HD boxes from eBay, Craig's list etc. Many of the boxes offered for "sale" out there are in fact leased boxes and DirecTV will refuse to activate them, so you will be left with an unusable piece of equipment. This even applies to boxes you might get from a relative - you can't use them, they need to be returned to DirecTV.