I work as a gardener and wanted something to wear to combat the cooler weather that didn't restrict my arms too much that jackets and such can. Bought this gilet from Sports Direct for £15 and am very pleased with it as it is lightweight yet very good as a wind blocker and insulator. http://www.sportsdirect.com/gelert-shell-gilet-mens-443258?colcode=44325803 Just used it tonight on the bike on a very stormy, wet journey and was extremely impressed. The front zips right up the neck to create a windproof seal around your throat; the lack of bulk allows it to fit inside your jacket and still allow free movement. Lovely and snug and can be worn off the bike with the 2 side pockets warm enough for your hands and fitted with zips if you need to store your keys, earplugs etc. Underneath the gilet I wore a short sleeve polo shirt with an EDZ base layer T shirt and was very comfortable. Good bit of kit for not much money!
I've worn a very similar thing by craghoppers to good effect. If you keep your core warm the rest will follow!