I've used Quicksilver for clipboard history historically. There is a currently a bug that I've been meaning to delve into: https://github.com/quicksilver/Quicksilver/issues/2913 but still generally usable. Particularly handy combined with adding simple AppleScript or JXA actions to manipulate the content (I have several simple ones for example to run a regex, to clean extraneous content around a number, a phone number, strip whitespace, indent 4 spaces for pasting into a markdown codeblock on SO, etc etc).

The Shelf plug-in also very handy along similar lines.