I don't think so. The only real similarity is the feeding tentacles, and even those are quite different. I think that is probably as a result of parallel evolution, since Paramites appear to be arthropods of some sort, whereas Sligs are vertebrates [as we have seen pistures of their skeletons]. Besides, we are fairly certain that Sligs are fairly closely related to Glukkons.
As for the Genetic Engineering thing, I think I can confidently say that that isn't true, since we already know that Sligs [whatever their natural habitat] were Sligs before they were enslaved by the Glukkons. Besides, they're hardly the "perfect soldiers"...
