So, I actually went out and bought an Acer Revo 3610 with Atom 330 Ion graphics, 2GB of RAM and 250GB HDD. I immediately installed Ubuntu because the native Linpus Linux wasn’t doing it for me and I am happier with Ubuntu.
I had a spare PCTV 74e DVB-T tuner and while this didn’t have drivers when I started that didn’t stop me preparing the machine. Thankfully Devin at KernelLabs was working on the drivers and they worked first time (well after I removed the firewire devices from the v4l compile!).
I have now been using MythTV for two weeks and I am not sure it is working for me, it has all the headline features but it is rough around the edges. Not homogeneous and I keep finding things that don’t work quite right. I think the developments with the new Freeview HD products from my company are really going to fill the gap here and I will probably end up going back to an STB with a PC for everything else. Time will tell, the Humax Freeview HD recorder isn’t ready yet!