Heard nothing but good things about Darren Woods who are based in Bredbury neck-of-the-woods. Further south of Manchester, in Stockport, is BayMoW
www.baymow.co.uk (next to Stepping Hill Hospital) who have looked after me very well over the last year or so.
Whereabout in Manchester would you prefer - BM Tec are central (in Salford) whereas the other you mention, in Warrington, is a bit of a trek out...