I added a woodworking vise to my workbench. I bought it from Lee Valley Tools. It has a jaw width of 9" and a maximum open size of 13".
Designed for easy adjustment, this vise has steel spindles and large cast-iron faces. The movable jaw has a slight inward cant to let the top of the jaw touch first as it closes. The quick-release function is very useful for one-handed operation. The vise also has an adjustable steel dog.
The installation was simple and straight forward, but did I mention the vise is heavy! It sits about 1/16" below the surface of the workbench. I also added 10" wide wooden face-plate attachments to the jaws to protect my work when using the vise.
This is an excellent quality vise. It wasn't cheap, but it will last me a lifetime.