Be noted most of the Bartons are now Multi locked and not unlockable. So get the NS7 and hope for good FSB overclock if you get a locked one.
Multi lock issue:
http://forum.oc-forums.com/vb/showth...hreadid=244237
Oh and the most certainly DO make a Barton 2600+.
http://www.amdboard.com/barton2600.html
2 seconds on google. You do better research AXDA2600DKV3D.