Power looks alright for both cards.

Maybe someone else can comment on the board. Sticking the 2nd card into the PCIe x1 slot may degrade the mining performance.

Something to consider...
Maybe you want to expand the set-up later on.
Look for sale items, maybe you can get a decent 750W power supply later on that can supply more cards.
I would personally go for a board that has more PCIex16 slots. Then you can always add more later on and do not need to scrap your entire rig, when you get tired of it.