In reply to fxceltic: your thinking is right
Most of the time a Pertex wind top is all you need unless it is foul outside, then some people do like using light waterproofs
for windproof, Pertex type options, Ron Hill, Rab, Montane and others, problem is with this type of jacket is you need to know what you are looking at, many of the mainstream run jackets are "microfibre" and not windproof or that water resistant, and they charge the price of the ones above. look for a jacket with no lining to it and has a slight shine on the inside of the fabric, this means its is "calendered" and will give better weather protection, wear long sleeve base layer underneath for comfort
for waterproof, same Ron, Rab, Montane, Marmot all have jackets at around £140 quid that are light and as breathable as it gets for the money
HTH