I use a torpedo style weight on my downrigger. I don't think you will need to worry too much about blowback because the deepest I have fished on erie is 80-100 ft and as long as you have 10 lb or so weights. Its also nice to have some smaller weights for shallower fishing (browns in spring and early walleyes or inland lakes). A guy on another fishing site makes the torpedos and they are great weights at a good price. They are not coated or anything when I get them but I spray them with the electrical tape in a can, black. I think they are 10-12 lb and have little blowback. I use blacks releases as they can be adjusted easily.

I have a depth raider on my boat, came with it when I bought it and like it. I believe I have caught more fish with its help and am planning on upgrading to a fishhawk when I get some money saved up. Biggest difference is that the fishhawk does not need coated cable on the downrigger as there are minor issues with the cable.