How to choose accessories for UHD resolution?

Question

Iron

Hello! I decided to assemble a PC for work, here is what is currently selected:
1) Core i5 6500 processor
2) ASRock H170M-ITX / AC motherboard
3) Crucial Ballistix Elite 16GB (8GBx2) RAM
4) 27 inch Dell P2715Q with UHD
resolution 2 points:
1. I'm not going to play and work with heavy graphics, and therefore I would not want to overpay for an external video card, but I'm not sure that the integrated Intel HD Graphics 530 will pull such a resolution without brakes (the specification says that there is support for 4K) .
2. What power supply is needed for a similar configuration in a mini-ITX case with and without external video?
It would be desirable to hear opinion of the people understanding iron.