If you want multi procs use hybrid weapons. No reason to ever use rainbow anymore now that these are out and cheap on exchange. Procs aren't all that reliable in STF besides disruptor breach though, best to just use all [Borg] disruptors, you can't ever go wrong there.
Also isn't the private STF channel just called EliteSTF and not PublicEliteSTF? I am a member of the PublicEliteSTF channel that doesn't require invite and the EliteSTF channel that does require one, not sure if there is another channel also called PublicEliteSTF that does require invites to get in.