Since my guides are related to Clojure. I might as well write a guide of what my clojure setup looks like and also what resources I read to write clojure code.
Emacs. I don't think there is more flexability when it comes it. You can also try GitHub's Atom Text Editor.
For Atom you may need to download a few plugins before working with clojure code. Like Downloading the proto-nrepl. Paraindent and etc.
After having emacs go ahead and get the emacs live one which is absolutely almost necessary to write in any lisp dialect.
Emacs live might be a little tricky to install but they have an easy install on their repo and typing the following should install emacs live in just one line.
bash <(curl -fksSL https://raw.github.com/overtone/emacs-live/master/installer/install-emacs-live.sh)
If you truely want to you can see my personal additions to emacs here.
Useful resources: