For Monero you better buy AMD. Best Nvidia miner is XMR-STAK-NVIDIA, also for CPU, but it's only for Windows. For AMD best hashrate has SGminer, but I recommend XMR-STAK-AMD, I like it much more, it's based on Wolf's Miner. Claymore is worst option.
Thanks! Very easy to complle on Arch Linux and getting ~325 H/s with an i7-4770. I was only getting ~200 H/s with cpuminer-opt.