Thanks to everyone for the ideas-

I tried the Lazer helmets and my head is too small for them (all the ones I've seen seem to come in just one size).

Miranda- I have a different Terry jersey with a mesh back that I am saving for the summer! I like those side-loading cages, but the placement of the bolts for the bottle cages on my bike and frame size (44 cm) just allow the small bottle to fit. I guess I'll plan to stop at a lot of convenience stores for water this summer.

Wanzar- my husband does trail-running and often wears his helmet when running down rocky trails. Thanks for your experience - I am leaning toward the sweep.....