Which graphic card falls under NVIDIA Quadro series

I want to know which graphic cards in the market falls under NVIDIA Quadro series. For a friends gaming pc I have to recommend a high end card. I had seen some models which looks like NVIDIA Quadro series, but I am not sure about the same. I am looking for the list of official Nvidia models. But yet I cannot find anything. I hope there will be models yet available for the same. I tried checking on the official site but it looks more confusing. I just need advice on two to three quadro series graphic card.

NVIDIA Quadro is a new high end series. There are five cards in this category. They are NVIDIA Quadro K5200, NVIDIA Quadro K4200, NVIDIA Quadro K2200, NVIDIA Quadro K620 and NVIDIA Quadro K420. This cards are amazing and features good performance. But there is a huge different in the specification. So check properly before buying anyone among this. Also there will be a quiet difference between the price also. The card is designed to give you nice output and good performance. But the price is yet not clarified.

NVIDIA Quadro series is designed for professionals. Who want a card which is ideal for photo and video editing work. If you are using Autodesk, or Solidworks kind of applications then you can surely benefit from such cards. Quadro K5200 is the most high end one that offers 2304 Cuda Cores. It provides you 8GB memory and 192Gb/s of Memory Bandwidth. It consume maximum 150w of power. Quadro K420 in the series i the lowest one. There are 5 models from low to high end usage.