The nvidia P106-100, based on 1060 gpu, has the same performance, price and consumption as GTX 1060. But you can not resell it to gamers, so I think it's better to stick to GTX 1060.
I know about P104-100 only that is based on 1070 gpu and it comes with a price of 350-400 usd. Probably it has the same performance as a GTX 1070. In that case it's better to look for the gaming versions.
https://steemit.com/bitcoin/@steem-buzz/hashrate-and-consumption-of-nvidia-mining-cards-p106-100
You can check this page from time to time, you can find some cards on stock for really good prices:
http://cryptowizzard.com/graphics-cards/