I'm willing to help you out on this! I'm a master with the PC industry.
Help me answer these questions please so I can give you the best of what you actually need.
1. What is the exact amount you are willing to spend?
2. What do you want to do with your PC? Just gaming in general? Or all you care about is Arma 3? Are you going to make a video editing and want to stream your games?
3. If all you care about is gaming, Do you want a high refresh rate monitor Like 100hz and 144hz etc? or normal 60hz
4. what resolution do want to play on? 4k, 1440p or 1080p.
5. Do you want RGB in your system? "Christmas tree" on your desk.
Sorry I'm too serious but I have to be like that. Trust me, I can give you the best value for your money. I can't just put PC parts without a single information
Oh sorry I just saw that you already own the 7700k. Ok we can start from here.
Is the 7700k used or compliantly new? If it's compliantly new and never been used, then I highly recommend you to sell it with the original MSRP price if you can! Or maybe 50$ cheaper.