This build is going to be a HTPC and NAS once it is finished. I will be building this over the next 6 months. Anyway here is the schedule/plan:
APU: 5400K, 6400K and 7850K confirmed more apu's and cpu's may be tested. 5400K i have, 6400K will replace it next month once the 5400k has been tested with new ram
Motherboard: The HTPC motherboard is a Asus A88XM plus. at some point i will definitely be getting a beast atx board to see what these apu's are made of, however the final build will be matx. asus board is in the post on the way.
RAM: not decided on this yet, it will most likely be whatever 2400/2666mhz ram is on offer
GPU: R9 295X2 
Case: Lian Li PC-C50B HTPC case, because it looks nice, is matx, has decent airflow and will last forever and still look nice.
PSU: this will be something that is low wattage and 80+ bronze around 400-500w depending on what i decide
HDD: 2X2tb hdds + 60gb ssd. one 2tb drive for recording tv/movies. the other will be my nas drive for all my other pc's to back up and share files.
TV tuner PCIE card: not sure on this one. something that can record 2 or 4 things at once.
Got the first bit today. the 5400K has landed. It is a brand new cpu with a pathetic stock cooler bought from OCUK for £39.95
it may be pathetic but it is magic 
more coming soon..........................................