You don't need anything fast, but choose good quality components.
Seasonic power supply, e.g. Seasonic G 450.
Intel Core i3 processor
No need for an add in graphics card
4GB RAM
Micro-ATX motherboard, with socket to match CPU (socket 1150 for intel Core i3 4...)
1 TB hard drive, e.g Seagate barracuda 1TB