For the last year I have been using a Sunbeam 10" electric knife to cut my finished ribs. It has served me well but I can tell it is getting a bit worn - there is a little play in the blades. I am not ready to toss it but I am keeping an eye on it.
To trim my ribs down I use an Old Hickory carving knife - 10.5 inches. It has a curve at the tip and it handles the cartliage easliy.