Well for the psu I'd say Corsair hx series hx850, installed one for my friend and it has been rather dependable. It is nice having the modular function, always a plus to help eliminate clutter and improve air flow. Can't go wrong with that.
I'd say stick with the Cooler Master HAF X, don't bog yourself with so many options. One thing I like about that case is the cable management, which will work even better with the modular psu. Also, I know it is a case you can use for new builds in the future.
Well I hope that helps, it seems your selections were pretty spot on. Asking for second opinions is pretty smart, but I wouldn't second guess it. For a first build just go with it, and find what works for you.