You could borrow John's Hurricane top to try...on second thought it may be a little big. They are the nutz when it gets a little cold. Only drawback is that it isn't breathable.
Actually I have used (and still do) Gill's dingy racing jacket for summertime fishing thru sept. It is light and very comfortable. Not fully waterproof like an evoII but for days when it is 60 deg+ it is great. Also you can slip a sweater inside if you have to. When I get serious I put on the skinz.