Stroud Green windows were good for us, replacing bay sash windows. Based on Stroud Green Road. We got wooden frames but they are a lot more expensive than UPVc. On reflection, some of the UPVC windows look just like wood so probably would have got that instead had we thought it through more at the time. Our wood windows were high quality and no issues at all with the install, just not convinced there was any great gain getting wood over UPVC given the significant price difference.
We are gradually replacing our original sash windows with identical wooden double glazed ones. (We are in the Clyde Road conservation area N15 although not many people seem to comply with the requirements) gosh they are expensive but lovely from Ward Glass who are a dream to deal with
whoever you go with, make sure they are FENSA registered.