Thoughts on Wyoming Rainbow(s)...
I agree with an earlier poster regarding the lightest line possible. Fishing in PA impounds I often use 2lb mono on noodle rods for rainbows/browns through the ice. Yes, you will break more fish off, but the increased number of strikes will more than make up for it...and as you become more adept at 'fighting' fish with the light line you will eventually put more trout on the ice (as opposed to under the ice - smile)
Thoughts on Pike...
I use 25# Dacron on all my tip-ups. As for leader type and length, I suppose that depends on the weight class of the fish in the lake(s). Being that the majority of the pike in PA lakes don't exceed 10# I use 6lb spidermono leaders when targeting Pike. Very rarely do you lose the fish, unless it is a trophy class fish, and you reduce the visible marker attached to the bait. You can always switch to steel leaders if you lose too many fish, or try heavier mono leaders.
Do these leaders come pre-tied? I don't know about you guys, but I think it is rather difficult to attach treble hooks to line with diameter greater than 20# test.