Help me with my CPU pick.

I currently have an i5-8400 which is due for an upgrade (I have an 3060). I need a solid cpu which will run games like fortnite on 120fps in 1440p. My budget is 720£ (i know i don’t need that much) but keep in mind i also want to upgrade the gpu sooner or later so a cpu that could uphold a 4070 super would be nice aswell. Thanks