My pholosophy on rain riding is that you're going to get wet anyway, whether from rain or sweat. What you want from your clothing is to keep your core warm. But you still need your arms and legs for radiator surface, because even in a cold rain you are producing a lot of heat while riding.
My favorite rain gear is a cheapie plastic rain jacket with the arms cut off at the elbows. That leaves me some radiator surface and the water doesn't run down my forearms to pool at my elbows. Ideally it will be a pullover, because water always pools on a fold or two in front and will eventually soak through any storm flap/zipper combination. It's not the getting wet part that bothers me, but a leak usually means an unpleasant cold spot.
IMHO it's best to forget the rain pants. Bents don't require padded shorts, so just wear unpadded shorts (or tights if it's cold) with coolmax underwear. The combination will dry quickly and being wet there doesn't affect your core temperature as much as losing all that radiator surface would.
As far as the bike goes, if you have a foam pad, always cover it with a shower cap when you encounter rain. A front fairing will work amazingly well in a light rain and provide some coverage even in heavy rains. And of course, if you ride in rain very often, you should have fenders.
