TabKeys lets you assign custom keyboard shortcuts for common tab actions in Safari. Available actions are: opening a new tab, closing the active tab, refreshing the active tab, and switching to the next or previous tab.
For each action, you can assign any character as a shortcut (including ones that you type in combination with the Shift or Option key). For example, you can assign lowercase “w” or uppercase “W” to Close Tab. (Only one character per action, for now. Later versions may support multiple character assignments for each action.) Only character keys are supported, not special keys such as the arrow keys or key combinations involving the Command key (or the Win key in Windows).