Advice on building a new HTPC

Hello.

I am building an HTPC, which has got to be quiet and efficient. It will not be used for gaming, but has to be capable of producing full 1080p picture quality/playing blu-ray.

The computer is going to be plugged into my tv in the lounge and I eventually intend to wire cat6 all over my house, via a gigabyte router - so I can stream live or recorded tv to two other televisions via media extenders.

I also have a sat dish with twin lnb and an external aerial, so the computer has got to be capable (in the unlikely event) of recording two channels, whilst allowing live tv to be watched in the living room as well as streaming a recording to one of the media extenders all at the same time - this will not happen very often, but probably will happen eventually.

The computer is going to be used as a replacement for my DVR, so it needs to come out of sleep mode properly and come on automatically to record and return to S3 afterwards.

I have come up with the following spec machine and would be really grateful for you comments and any changes you would suggest - or any incompatibilities I may have missed.

Hard drive - F3 1TB Samsung (I looked at 5400 rpm hard drives, but although they are quieter, decided that I would need a 7,200 rpm hard drive for simultaneous recording and streaming)

PSU - Corsari 550VX

Mobo - Asus MSN78-EM (this has 2 x pci slots, 1x pci 1 and 1 x pci 16 and NVIDIA GeForce 8300 chipset)

TV Tuner cards (three of them) - 2 PCI Hauppage WinTV Nova HD S2 Tuner cards (for two freesat channels) and 1 Hauppauge HVR 2200 MCE Dual Hybrid PCI Express card (for two digital channels)

Case - Antec Fusion Remote Max

CPU - Athlon II x2 240

OS - Windows 7, using media centre as the front end

Optical Drive - LG Blu-Ray

RAM - 2 x 2GB 800Mhz DDR2 RAM (I know that 2GB would be enough, but RAM is pretty cheap so thought I would go the whole hog)

Your comments would be greatly appreciated before I take the plunge

Thx