Mosty a creepy spandex wearer here... but if you don't want to wear spandex you don't have to. Rain pants though... I'd just forget them and go with something that is rain resistant, or better yet, just quick to dry, but also cute. Rain pants usually just make you as wet as the rain, from the inside out...

I've seen people make pretty snazzy looking riding pants by altering nice wool dress pants from the thrift shop into capri length, sometime even knicker style (drawstring or other type of closure to keep pants out of drive trains) Of course if your 3 speed has a chain guard, it doesn't even matter. You can get stuff like this at a few places directed towards those who want to look like hipsters, but have cash - it's usually $$$$...