Pittsburgh stinks this year. Kordell is a big part of the problem but hardly the whole problem. You will likely see a poor first half by the Steelers, followed by a QB change which will lead to an equally poor second half. Forget Ward.
Of your choices, I like Moulds and Kevin Johnson. Quincy Morgan has been a non-factor since week 1 and will probably remain such unless Holcomb returns at some point, so Kevin isn't really 'dividing yards and touchdowns' with two other receivers, at least not any more than any other team's #1 receiver.
I agree with joe_montana that Keyshawn needs to prove himself before he can be considered a starter again.