Rab, Mountain Equipment and Montane are good UK brands. I find ME tend to have a more athletic alpinist fit, whereas rab jackets are more voluminous so you can pull them on over everything else e.g. on a belay. Rab Photon Pro is a well known synthetic insulated jacket for Scottish winter conditions. I agree on Acteryx - good but over-priced and becoming the outdoor poseur's garment of choice. You can also get some real bargains for perfectly adequate clothing in Decathlon.