....Having had a chance to speak to my better half it has become clear that a specific requirement would be to have access to both Freeview and FreeSat with this system.......
Have access to, or be able to record from? - I ask because it is my intention to use the TV aerial feed to connect the television tuners, and use the satellite feeds for linuxmce. What advantage is there in having freeview? What does it have that freesat doesn't? Freesat already has HD transmissions supported with DVB-S2 tuners. Freeview are starting a trial of terrestrial HD, and HD supporting DVB-T tuners do not exist yet. The freeview landscape is likely to change after the analogue switch off (2012?), Satellite is a known quantity, supported and well understood. It seems to me that to make a system likely to be good for 3-5 years, I'm better focussing on satellite at the moment. Just my own thoughts, of course (about the system in the UK, not applicable elsewhere).
Now I haven't tried it myself, but totallymaxed has had four USB tuners hanging off a dual atom board. I see no reason why you couldn't have two of each, if you so wanted. No guarantees, you'd have to take a punt. I intend to use satellite (including both freesat and a motorised dish) only for linuxmce.
Personally I'd be nervous about a single core as a core/hybrid, but there are no problems as a media director.
Following on from the post below for having an Atom 330 as a core. What do people think of the Zotac ION Mag Nettop (MAG HD-ND01) as a hybrid if it will only be used for a small network (ie two other Media Directors)?
It has a dual core Atom (330) processor and 2GB RAM.
If you have a NAS and a USB or Network Tuner (like the HD HomeRun), then could the Zotac Mag be used for a hybrid?
It has a Gigabit NIC and Wifi (802.11n) . Has anyone been able to make the Wifi act as Eth0 (for connecting to the Internet) and the NIC as Eth1 (for the LinuxMCE network)? Or would a USB NIC be needed (to have two NICs)?....
I don't see any reason that it couldn't be used as a hybrid, but the load on it in it's role as a media director would detract from it's throughput as a core, and vica versa. You'd have to try it. It would be interesting to know how many concurrent TV recordings from USB tuners it could do, while playing a HD video. I suspect two at the best.
I also suspect that you might want to put plenty of memory in it (I know there are those who say a Linuxmce system doesn't need much memory, but with a slow processor I would want to max it out so it never becomes a limiter of the system - RAM is cheap, and I'd put 4Gb in it).
I've not tried this (although going to use some atom boards, but not as a hybrid).
As for the wifi as an ethernet connection: I've never heard anything about that, but would imagine it might be technically possible. After all it's just another pipe as far as the machine is concerned. How well Linuxmce could accomodate it, I really don't know. I suspect not well. You need advice from someone who knows the system well for that.