https://github.com/tmux-plugins/tmux-fpp
https://github.com/tmux-plugins/tmux-copycat
https://github.com/Morantron/tmux-fingers
https://github.com/tmux-plugins/tmux-urlview
Any configuration or plugin that leans on the built-ins is probably going to be faster, so consider that w/r/t tmux-copycat.
I also really like tmux-resurrect, which saves and restores sessions for you; tmux-continuum, which runs those automatically; and the tmux-zen plugin for Oh-My-Fish:
https://github.com/tmux-plugins/tmux-resurrect
https://github.com/tmux-plugins/tmux-continuum
https://github.com/sagebind/tmux-zen/tree/master
It's pretty easy to get a very nice tmux setup going!