Besides, You got the Ori skins already.
You should already have replicator air skins, the base, all you gotta do is just create some MK.1s, spider replicators, and human replicator skins for ground units.
If not, you could always work on the maps after the mod is completed, and then release them for download once your done. Artists wouldn't be involved in any bug fixes or any coding, so you could always give them the job.