Millets is a great store for outdoor and weather proof gear. They have a great selection and have shops all over London (my local one is in Enfield). Got a great pocket waterproof one there (you can stuff it into it's own pocket so it forms a small package you can carry around) but it's an actual jacket not just a plasticky overall. Have a look for yourself:
Sprayway do good quality breathable jackets. The Berghaus RG-1 is pretty decent and, unless you're imitating going from arduous course to spelling test, the difference in breathability between them and Goretex ones won't be noticeable.
Stay away from the piece of crap, my arms get soaking wet (dunno if its sweat or not) just walking.
It comes with a Ski Skirt zip type arrangement which I sewed to a set of DPM 'goretex' pants, having them pants zipped in is the only thing that stops the jacket riding up when you have a pack on, the pants are shit if you sit on a spongy scottish mountainside, you get a cold very wet arse, they have a NSN so are issue right??
I now carry a pice of neoprene in a plastic bag, its bad enough having your back sweat run down your arse crack, 3 layer breathable goretex.....my sweaty wet arse (and back and arms).
Atomic Montane is pretty good. Comes with a hood (better than a hat since it can't blow off), has a bit of wire in the peak, so you can see where you're going in a gale and wraps up to the size of your fist. Very light-weight too.
I once popped into Decathlon not too far from me and picked up a cracking lightweight breathable/stretch fabric jacket for £70. Pockets could be a touch bigger (esp the chest one) but a cracking adjustable hood and pit zips too - looks pretty decent. Only thing I would suggest is that the sizes are a bit weird.
Keela Munro jacket in red / black , I only wear a decent baselayer under it on the hills and I'm warm , certainly not a fashion jacket but if you need a great working jacket I'd have a look as it tough and has plenty of room in the arms and decent size pockets , the wired hood is great in either snow or heavy rain etc only thing I'd say is the sizing as I went done in size from what I would have had in other brands .... Oh and it's far to warm to wear mid summer.
If its worn daily then you'll need to re-proof every month just to keep the waterproofing up to scratch .