Which graphics card is the best? (AMD it seems)
What motherboard? How much RAM?
Also, how much bandwidth will such an installation use?
On which cryptocurrency would you go first?
Thanks a lot for your reply!
I would suggest to read the mining Guru's, they have a good farm with lots of information
https://bitcointalksearch.org/topic/data-center-mining-garage-and-man-mining-cave-1761303
https://bitcointalksearch.org/topic/data-center-mining-garage-and-man-mining-cave-1761303
with a decent Miner
https://bitcointalksearch.org/topic/claymores-zcashbtg-amd-gpu-miner-v126-windowslinux-1670733
https://bitcointalksearch.org/topic/claymores-dual-ethereum-amdnvidia-gpu-miner-v150-windowslinux-1433925
https://bitcointalksearch.org/topic/ewbfs-cuda-zcash-miner-1707546
https://bitcointalksearch.org/topic/mining-os-simpleminingnet-manage-your-gpu-farm-the-easy-way-30-days-free-1541084