If you plan on keeping the same CPU, you can keep the same ram.
Not sure on Mobo though. Idk if Dell uses a custom board with who knows what for mounting holes lol.
Case is personal preference. Now is the time to decide you want want a small case, mid size or large case. That would help with other options.
Use pcpartpicker.com to find a case u like. Offhand, this isn't a bad go-to case/mobo combo for the mid size range.
https://pcpartpicker.com/list/VgQ7bvSince u gave $600 though, you can definitely upgrade cpu/Mobo/ram/case to something like...
https://pcpartpicker.com/list/JnMFr7Could sell ur 4790k for $200ish maybe? Not sure. I usually sell full builds.
This post was edited by Penguins0690 on Apr 23 2017 01:30am