I have a Rab VapourRise jacket. Perfect for regulating temperature and reasonably warm. Normally around £125 but a bit of research and a price match and extra 10% off at Go Outdoors took it down to just above £60.
My warm coat is Mountain Equipment, Triton. I haven't had it long but wore it in -4 temperatures yesterday with just a tshirt underneath and I was still very cosy. It's a down filled jacket but doesn't have the 'pockets' on the outside like most down jackets. It's also waterproof. Again, being a bargain hunter I managed to get this much cheaper though price matching etc. Very pleased with it so far!
I have a few pairs of trousers and Montane Terra/Super Terra fit me very well. Also excellent quality and windproof, not waterproof though. If you tried a pair on and liked them, they can usually be found on eBay, used once/with little use.
Getting decent boots would be the biggest thing for me if you're going to be walking far. A certain brand would be hard to recommend because our feet are all so different. You'd have to try various pairs on in store. I spent a fair amount on boots but feel they are so important, again I did I price match at go outdoors and got a £180 pair for around £110.