Bud- NOT an "expert". Just been in the biz for a while. I sell them and get questions on a daily basis, so I need to know the basics and functions. (Finalization, editing, disc compatibility, etc.) As Chris suggests, you may consider a hard drive DVR, IF you can find one. Unfortunately, to PURCHASE and NOT rent , they are very hard to find, unlike several years ago. The DVR's WITH hard drives, are even more scarce. One manufacturer that makes an HD DVR without a hard drive, is Tivo. They use CableCard(s) for decoding HD broadcasts. Not sure of that formats future, had "issues" from the start. Certain TV manufacturers used it, but cable providers never seemed to support it. (Promoted THEIR own cable boxes to rent instead) Stand alone DVD Recorders WITHOUT hard drives ARE abundant, as you have probably seen. DON'T expect the upconverting, (upscaling) feature on them to give you Hi-Def quality, not even close. If anything, a slight improvement over standard DVD, using HDMI. There was talk of Blu-Ray DVD Recorders a while back. Just hasn't happened, yet. Most manufacturers assume people will "rent" DVR's from their cable or satellite provider, rather than buy them. Also the digital QAM tuner may enable you to decode HD broadcasts, if your cable provider isn't blocking them. Usually for the major networks only. (ABC, CBS, FOX, NBC, and PBS)
P.S.- I bought a Sony RDR-HX900 DVD recorder with a 160 GB Hard Drive several years ago.
I use it EVERY day and can store about 60 hours of programming with almost DVD quality. Can dub from the hard drive onto multiple formats of DVD, even at high speed. (Excluding DVD-RAM, Panasonic's preference) You may be able to find one, or something similar, on Ebay, etc. Probably used or refurbed. Good Luck.
P.S.S.- Agree with Don, (drpertz) regarding the quality of HDMI cables. While you dion't have to go "overboard" with high end cables, they need to be capable of passing the "bandwidth" that the source and TV is capable of. Obviously the larger the screen, the more apparent the image quality difference will be. JMO.