I like the Oxford two piece. Around $40 top and $40 bottom half. I tried them on in the shop and bought XXL top to fit over the leather jacket and XL bottom half. Have worn them a number of times in the rain from light to very heavy rain and stayed 95% dry. They are also good in cold weather as a wind block. I think the two piece are easier to put on too.
http://www.oxfordproducts.com/motorcycle...rain_wear/
http://www.oxfordproducts.com/motorcycle...rain_wear/