hey sandlizard, out of curiosity, did you ride north-->south? or south to north?
I agree with layers: merino wool layers. start going to goodwill - seriously. I pick merino stuff up all the time for a few dollars so that I have a variety of weights, and merino is very fine and non itchy wool that wont smell. I'm pretty preferential to the banana republic extrafine italian merino zip-necks i found a pair of. Basically bike jerseys without the silly back pockets. I think i paid 2 dollars each.
for a jacket i got a sierra designs nylon shell with vents for 5 bucks, that was a lucky find. but any cheapo thats light, and plastic and vented is your friend...