In reply to Ella Morris:
How much money do you want to spend and how serious usage is it likely to face? i.e. you might want considerably more jacket if your walking is Northern Highlands Munros than if its summer strolls along the SW Coastal Path for example. Best value for money is almost certainly going to be something from Decathlon, but Alpkit is worth a look if you don't have loads of cash but still want something designed for "serious" use.