I would tend to use DEVONthink for this kind of task.
There are scripts for integrating DEVONthink with Sente, and for integrating DEVONthink with OmniFocus 1.

(The scripting future for OmniFocus2 seems uncertain, to judge by the recently released Omnigraffle 6, which is unable to run most of the complex scripts which run on OmniGraffle 5).