I tried the bottom bouncer from Northland, pencil shape.  They are made out of steel so you don't have the lead issue.  They are fairly expensive.  I was disappointed because I got snagged in rocks a lot more than I expected.  They worked fine for trolling for trout in deeper water, but that's not they were designed to do.  They are also a little awkward to use and tends to twist around the line when not in the water. 

I fished with my brother-in-law in North Dakota on one of the reservoirs with bottom bouncers.  We didn't have much trouble with snagging, but the bottom was more clay than rocks.  Plus, he knew what he was doing.