Lowers usually come either "stripped" or "complete".
Stripped lowers are like the first you posted. They are literally just the shell that begins a build.
A complete lower contains all the parts necessary to attach and upper receiver and open fire. It contains a lower parts kit, fire control group, grip, buffer tube, buffer, and spring. Cost goes up, but its ready to go basically.
Do you have a budget in mind?
"You'll Never Walk Alone"
Last edited by david05111; 01-04-2013 at 12:50 AM.