I use brushless motors with helicopters, the difference betwen brushed and brushless in this application is chalk and cheese. Much more power, using the same battery source, and much much cooler, no sparking of brushes. They HAVE to have a compatible brushless ecs, will not work without, and generally are lipo battery powered, again, weight, important in a rc heli. Make sure before buying the esc that the motor is compatable amperage, otherwise it will keep shutting down and may not work at all. I had a quick look at that ebay store, the ecs you are looking at is not enough amps for the motors they list, also make sure the motor is an inrunner, not outrunner, that has a can that spins and the armature is fixed, onvoiusly no good for a boat!
I personally would buy in the uk, support the local model shop, and any probs you can go back. In the heli world, I have seen on other forums people have bought some junk from overseas that could not be returned, just to save a few quid. Lipo's are a tad unstable, get hot, and have a short run time, beware!