I'm up to the stage where I need to get the recording functionality working. That was the major selling point to my wife. So I bought an Aver Media DVB-T 777 second hand from eBay on the recommendation of a mate. The reason he has it, and that he suggested it to me, was that it plays nicely with Linux as the Phillips SAA7134 chipset is well supported in the Linux kernel. I'm currently using version 2.6.31-gentoo-r6, with this config
--> Multimedia Support
<*> Video For Linux
<*> DVB for Linux
[*] Video capture adapters -->
<*> Phillips SAA7134 support
<*> Phillips SAA7134 DMA audio support
<*> DVB/ATSC Support for saa7134 based TV cards
Compile, reboot, and done. TV card supported.
I emerged media-tv/mythtv-0.22_p23069 and followed the instructions on the MythTV wiki for configuring the backend.
When running mythtv-setup, if all you have is a keyboard, the left and right arrows allow you select options from combo boxes, the up and down arrows select combo boxes, buttons, text fields, etc and ENTER/RETURN selects whatever is highlighted. You'll get the hang of it.
When selecting your capture card, make sure that you select the DVB under the card type. In the case of my card, because I had multiple inputs (there's an S-Video adapter) I didn't change the card type, so I spent a lot of time figuring out what I couldn't scan for channels. The DVB "section" of your card is the antenna port.
Once you quit mythtv-setup and run mythfilldatabase, if you get an error about not being able to create a QObject/widget start your backend again. This is a weird error with not much information to go on, and took me a lot of googling to figure out. It's because the backend can't be connected to, so starting it solves the problem.
Once I got MythTV configured, it was time to check out how to integrate it with XBMC. The inbuilt stuff to connect to a MythTV backend is buggy, causes XBMC to lock up, and isn't very feature rich.
However MythBox is the saviour of this piece. Has everything the wife would want. So I'm testing the recording abilities now, and can watch live tv. Once I do some more tweaking I should have a decent PVR in the HTPC.
I really do need to get a new HD though.