HTPC

Pondering making a Home Theatre PC rather than having umpteen boxes (Sky decoder, Freesat HD decoder, Samsung DVD/HDD recorder) so that we can resell those things. I have a CPU (AMD Athlon X2 BE-2350) and graphics card (NVidia 8500GT) and the motherboard I am currently using (MS-7349) has 7.1 sound and HDMI out. I have an 80GB hard drive no longer in use (I know it's not too big) but the two things I really need are a DVB-S PCI tuner card and some means of making an IRDa remote control. I figure that my Harmony can drive it all with no problem, but I need a receiver. Oh yeah, and a case, which may well have the IRDa on it since it will be one designed to be an HTPC?

I'm thinking of going Linux with MythTV as the PVR, but I need more info, particularly on what tuner card to get and how to do the IR stuff...

Update: It seems that Logitech do a mighty fine set of THX-approved 5.1 speakers (ignore the price, I can get them for roughly half the amount Logitech sell them for on their own shop). I would like to get these anyway, regardless of setting up the PVR.

Update 2: Got the Logitech sound system and very good it is too. In my researches, I've found I need a Hauppauge Nova-SE2 DVB-S2 card to receive the satellite signal and record it and mythbuntu is looking good as an all-in-one Linux solution. It's unlikely that my AMD Athlon X2 BE-2350 is sufficient to drive a HD signal unfortunately, so the price for this box is going up. Right now, Hauppage card: 100€, CPU: 70€, memory: 40€, hard drive: 50€, case: 60€, new mobo for main computer 120€, IR stuff?