Rexford,
Can we have more information about the judging process (deadlines, selection process, how many people will you have in your jury, any tools you already have ready for the juries to use)?
About shortlisting:
It all depends on your tools. If juries have an effective rating tool, they can check all the images in a multi-staged process without the need of external aid (i.e. the organizers).
In Colombia, for example, juries checked themselves all the participating images (about 2800 in WLM2014) without much trouble. In fact, the most difficult stages were, by far, the last ones, when they had to pick the top 10 among a bunch of good "surviving" images.
In your specific case, in order to mantain the integrity of the contest, I would suggest you NOT to process the images before the juries do it, as you told us that several people in your team also participated in the competition.
Cheers,
Oscar (Racso)