I need to buy the case, motherboard, ssd, harddrive, psu and gpus. what should i buy to get the best speed
I am a professional miner and I boot all of my rigs from a network hard drive (thus saving expense). I also have none of my rigs in a box... heat is your enemy! Focus on GPU and compare the number of "shaders" the card has. Divide the price by the number of shaders to get the most out of your money.
my humble opinion:
MOBO - ASRock 970 Extreme < has built in power switch and reset button < no case needed < room for 2 GPU's with large gap for air circulation between the cards < AMD3+ socket
CPU - AMD FX-8350 < 8 cores for CPU mining while you are GPU mining (dual mining)
RAM - 8g min
PSU - 1050w < you want your total rig to run at 85% of wattage capacity < My rigs with 2 GPU's and 1 CPU running full power use slightly less than .9kw/h
GPU - Radeon 7970 < hard to find right now due to Christmas and mining
Battery backup is critical...get largest capacity you can find...