Everything is great! However I'd change the case. It only comes with 2 fans, and IMO just looks old. Don't pick it just because it's the first thing that pops up on pcpartpicker
I am satisfied with what you have chosen based on your needs. I would recommend though going for a smaller PSU wattage since 750 would be overkill. 650 or even 600W will do the job.
Considering that the 750W B2 is on sale for $30 off I think he's more than smart to choose it.
And that's not overkill, a 390 can draw in 340W on a stress test.
It is an overkill. His system needs around 500W to operate stably, like most systems require around those specs. I have given it another 100W just to be sure and as a future investment for upgrades. And I truly believe that a Bronze PSU is quite a setback, provided that Platinum rated PSU's are now in the market, and considering that he is going a "latest technology" pc built.
Considering the B2 is made by Superflower and has a 6 year warranty, and has such headroom for the future, I think it's worth it. You can't buy a better PSU for that price with the sale it's been on these past days.
And going with a 600W PSU on a 500W load is inefficient. Bronze at half load is probably going to be more efficient than inefficient load on platinum. Plus the electricity is so little anyway.