The 8700 will easily run a GTX 1060 with the stock PSU.
you *MUST* upgrade to BIOS A10 for Win7/8/81 or A11 for Win10 or the card will not work.The BIOS update is needed for all GTX 900 series or higher cards.
Depending on the exact card you buy, may need an adapter for the power cable.the OEM power supply has two six pin connectors. Some of the 1060 cards have a single eight pin connector, and to power this you will need to use a reverse Y adapter to convert two six pin PCIE power connectors into a single 8 pin. Some cards come with this cable, otherwise they are about $5 shipped on eBay.
I suggest completely removing the nVidia drivers and re-installing new drivers from nVidia.
ps: My preference has been MSI Gaming cards. I have an MSI GTX 970 in one system and an MSI GTX 770 in another and they work very well.