The Pets at home store at bridgefoot roundabout sometimes have Malawi's in an "assorted Cichlid" tank. Not the best way to buy them but if you know what they are 1st its OK.
Also High Legh garden centre just outside warrington sometimes have a few but not a great choice.
A trip to Oasis in Salford would be well worth your while, its only 20 mins down the M62.