Which RX470?

[Dradden]

Currently looking to put 2 x Rx 470 in my rig to mine Ethereum.

I am just not sure which one would be best to get, has been quite awhile since I looked into vid cards!

https://www.newegg.ca/Product/ProductList.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&Description=rx+470&N=-1&isNodeId=1

I will probably need a new PSU? I think my current is like 650W running a AMD Black FX-8350, 16GB OCZ, Samsung 840 Pro SSD, and some old crappy vid card.