Since you mention both pbcopy and iTerm - I love https://github.com/skaji/remote-pbcopy-iterm2. I do most of the work on a remove Linux server, treating my MacBook as mostly a dumb terminal, and being able to transparently copy from the remove to my local clipboard is so nice.
I have tried it, but for whatever reason I just don't like it. I prefer just running tmux in iTerm with no integration.
On the topic, you can also integrate tmux with the native clipboard - I have set copy-pipe to the remote pbcopy, so any selection done in tmux get copied to my local clipboard. I also just found out that tmux also support it natively (https://github.com/tmux/tmux/wiki/Clipboard#the-set-clipboar...).