Kmart is just another outlet for Sears to sell their products in, the tools will not become watered down with less quality, they should have the same quarantee but depending on store location they might run different sales.
If your worried about quality tools start reading up on snap-on, if they keep up with their current pace snap-on could eventually be gone.
I've met tons of old timers who where Snap-on freaks, look into their so called life time guarantee and you will realize it's not true, try and return a Snap-on tool 20 years later when it breaks they will tell you sorry we can't do that, all those Snap-on guys are now Craftman guys, why cause you walk into Sear or now Kmart and they see the name and tell you go find what you need even 20 years later