Heddon Zara Spooks are a good surface lure, worked in the 'walk the dog' style. Frogs can be good as well, especially bouyant ones that have tantalising trailing legs, also just about any floating lure retrieved slowly will remain on the surface or just sub surface and work, a favourite being the old Fox mega mouse as they shift a lot of water.
Have you tried light spoons, these will stay quite shallow and some such as the Kuusamo come with weedless double hooks, there's also buzzbaits which are similar to spinnerbaits but have a rotating prop instead of the usual blades, theses will bulge just under the surface on a fastish retreave.
Phil