I’m using proto-repl, bracket matcher, lisp-paredit (mostly disabled, used for better auto indents), and parinfer (simply wonderful).
I based a lot of my setup on this gist [1]. My dotfiles are here [2]. I have it set up so that ‘zc’ connects to an nREPL, ‘zb’ evaluates the top block under the cursor, and ‘zz’ evaluates the entire file.