I agree with FG - between my 4 and 5 wt is a world of difference. Heck, maybe even a solar system. They're certainly different actions, but the 4 is much better suited to small trout and panfishies. The 5 is more of a western trout rod and sees occasional bass duty (plus spring and fall trout here in the mid-atlantic for the fat boys). I fish the 2-wt exclusively for super small trout streams and small ponds for little panfishies. I'd go with a fast- or medium-fast 3-wt.

Marty