Actually one of the BIG advantages of the EA-38 for cable/sat. people (with STBs) is using the EA-38's IR blaster you're able to program the EA-38 to automatically send out a IR signal to change the channel on your STB.
If you haven't found the IR blaster it's a ~4' wire with a LED on the end. You place the LED near your STBs IR receiver and program your EA-38 for the corresponding STB codes any you're good to go. When setting up your EA-38 it should ask for your brand of STB. You may have a choice of a couple different codes to try. Hopefully one will work. Note when you have a scheduled event programmed in your EA-38 you'll want to make sure to leave your STB ON. Otherwise the EA-38 will not be able to change it's channels and your STB will also probably not output a signal when off.
Since you have a HDTV you'll really want to get a HD STB. Otherwise the only way you'll be able to watch HDTV will be using your TVs built in tuner, which again won't get nearly as many channels as your digital STB will.
Lastly, depending on the STB you get it may or may not be able to output Wide Screen over it's S-video or composite outputs. If it won't output WS over SD outputs (S-video or composite) this will be a big hit for picture quality. All your digital recordings will be letterboxed. True you could use the zoom on your TV, but as others have found out this is less than ideal and produces a rather fuzzy picture. If I had cable I'd insist on a box that could output WS over S-video, that or I'd be getting a EZ-48 and hope the WS HD channels I wanted to record were "in the clear" channels.
Very few STBs seem to have "firewire" output but it wouldn't do you any good anyway. The DV input on any DVDR isn't firewire but more for recording from camcorders and such. Using a DVDR your best input will be the S-video input which is analog.
As you've notice Comcast HD isn't as good as OTA HD but it's a far site better than Comcast analog.
You'll want to run S-video and audio from your STB directly to your EA-38's line inputs and then HDMI from your EA-38 to one of your TVs HDMI input. Use this connection for only recording/playback and setting you recordings. To watch HD from your STB you'll want to watch using your STBs HDMI/DVI or component outputs which will go directly from your STB to TV. Anything routed through your EA-38 will be SD or upconverted SD. Not nearly as good as HD from either your TVs built in tuner or from your STB via it's HD outputs.
I really loved my little (32" 720p) Panny LCD, it was my first HDTV. Now that I've got my 46" 1080p Sony
the Panny is the bedroom TV
To bad your Panny TV didn't have the video output option. It would be a work around if your STB doesn't output WS over SD outputs. My Panny LCD did output WS over it's composite output.