In general i would recommend nothing less than a RX 470 ~170 EURs] for UE4. (or that overpriced 1060 3Gb that is practically ****, but still costs 33 EURs more [203 EURs])
In terms of CPUs… hard to make any decisions right now, because Intel will have to lower its prices in the next 5-6 weeks, when “Ryzen” launches… so i think it is a waste of money to buy any CPU right now. (i personally would wait that 5 weeks, and then decide to buy something)
Everything else is up to your personal Flavour.