The 4690k is plenty to get, especially if your going to use existing DDR3 RAM that you have. Personally DDR4 is nice and all, but I don't think it is that much better than a good set of DDR3, so if you have existing DDR3 RAM that your going to use, I would just stick to a Mobo that supports your DDR3 and get the CPU for that Mobo. The 4690k is plenty for any task and will do you extremely well for your needs, so I wouldn't worry about it at all.