Aurora R3, new graphics card upgrade

My old Aurora R3 finally needs a GPU upgrade.  It has the stock AMD 6870, which has been a great GPU for me for many years.  My R3 is an I-7 2600k, 8GB Ram and 875 w PSU.  What would be my best options to improve graphics performance?  I was thinking of spending up to $300.  Would a GTX 1060 or 1070 be compatible?  Maybe the newer 1660 or something in that range?  Thanks for any input you can provide.