I've come close, but being at work I have limited time...
Code:
LN21995 Antec NSK2480-UK V2 Desktop Media Centre Case for uATX with 380W Earthwatts PSU £85.04
LN25120 Asus M3N78-VM, NV GF 8200, SAM2+, PCI-E 2.0 (x16), DDR2 1066/667/533, SATA II, SATA RAID, uATX, VGA £52.43
LN25916 AMD Athlon 64 X2 7750+, Black Edition, AM2+, Kuma Core, Dual Core, 2.7GHz, 3MB Cache, Retail £45.76
LN14277 2GB (2x1GB) Corsair TwinX XMS2, DDR2 PC2-6400 (800), 240 Pins, Non-ECC Unbuffered, CAS 4-4-4-12 £26.04
LN22883 LiteOn DH-4O1S-06C Black 4x Internal BD-ROM Blu-Ray SATA OEM £50.59
LN26800 KWorld PE355-2T V2 PCI Express Dual Digital Media Center Remote £56.35
All from Scan so without having to pay for delivery it would come to a little over £310. No HDD or OS but as you say, with Windows 7 there for a little under a year you can use that. Comes with a remote, plays Blu-Ray and should be able to handle 1080p without a problem all through the onboard HDMI.
The BD player can't record to anything though, but if you weren't too bothered with BD playback as of yet you could always put a normal DVD-RW drive in there and save a few pennies, or spend it on more ram.
It's also difficult to know what style case to look for though, but that case is basically an Antec Fusion without the media display or remote, but you get the remote with the TV Tuner.