Electrac has been discontinued. I called Detroit Locker and they said that customers had a pain installing them and they weren't worth the hassle. This was a couple of months ago when I called, but it's still on their site. Drop them a line if you're considering.

 

I put this in my rear a few months ago in the winter.
http://www.powertrax.com/lockright.html
It was the most cost effective I could find.
I haven't had any issues with it on the street, and the truck is my daily driver.
I'm not sure why everyone keeps says that lockers are so taboo for the street. As long as you know how to drive, you'll be fine.

 

mainly what i was looking for was somthing for the rear i think im going to go with aussie in the front and try to find one for the rear