I’m buying computer parts online so that I can design levels and model for UE4. I do not plan on compiling from the source.
CPU: Intel i5 6500 3.3gHz quad-core
MoBo: Gigabyte GA-Z170-HD3P ATX LGA1151
Memory: G.Skill TridentZ Series 16GB DDR4-3200
SSD: Sandisk SSD PLUS 120GB
HDD: Seagate Barracuda 2TB 3.5" 7200RPM
Video Card: Gigabyte GeForce GTX 750 Ti 4GB
Have a look at this webpage. Here we describe minimum requirements for both developing with UE4 and running UE4. I highly recommend looking into the development section at the bottom of the page.