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As above suggestions for a jacket for a big ride in Scotland, cost upto £250/300 max
Gore Fusion, the one with the new Gore-Tex Active Shell which, so far at least, seems to be working out really well for me. It's certainly the most breathable proper waterproof I've ever owned. Just about packable enough to fit into a (decent sized) jersey pocket too.
I have a RAB love it wouldn't go back - but it is actually lightweight so maybe not for you
http://www.ultralightoutdoorgear.co.uk/rab_event_momentum_jacket.html
I also have a topend bombproof Mountain Hardwear - has lasted me 8 years of hell, including using as a layer over a motorbike leathers and it still perfect....only replaced it with the Rab as it was heavy.
Cheers, having a look at Rab stuff atm but will check Gore stuff out too.