ItzUrBoiChipsAhoy

But what motherboard would I get?

What if I hypothetically already bought the i5 9400f?

I currently have an i5-4430

I want to upgrade my CPU to an i5 9400f because of its value for performance. The only problem with this is my current motherboard doesn't have the right socket, so I am going to get a new motherboard as well. I don't know what motherboard to upgrade to, because I know very little about motherboards, so I need some help. I need 4 ram slots, and I am willing to spend about $100, but the lower the better. My current Mobo is the ASRock Fatal1ty z97 killer. Thanks in advance!

I am looking into building a pc for around $1000 (USD) and all I need is a keyboard and mouse, I already have windows too, I would appreciate it if you guys designed me a build (Including the mouse and keyboard) and its ok if you go about 100 over. I am going to play mostly games like overwatch and GTA five. Thanks! EDIT: I don't care how it looks and I would like a good enough case for upgradability. I also already have a 275GB SSD.