Honestly, I may not be the best person to ask if an IDE is what you want, heh. We usually just use it as an editor, and we don't really have much in the way of IDE features in vim either. But we also don't really use languages that practically need an IDE, like Java. Stuff like HTML and perl and JS are much easier to write with a normal text editor.
If you just need LSP autocomplete and such, though, Kate's got that! There's a plugin for it, I think. You might have to turn it on.