I already have a 3/4 helmet which should work well. The Verizon rain suit is awesome with rubber boots and suspender pants. we used to stuff our sleeves with paper towels to keep the rain out while working with hands held overhead.
And yes, thankfully it's not cold when it rains here.
I got caught in the rain riding home from work last month, but the water could NOT wipe away my big smile as I rode home.
