I have 2 kennels from TSC.
Originally I bought this 10x10x6 kennel (http://www.tractorsupply.com/en/store/preferred-dog-kennel-10-ft-l-x-10-ft-w-x-6-ft-h
) but now that acts as a fence for my run and the dog stays in a doc bob's 5x10x6 kennel while we're out.
The doc bob's is much nicer quality and seems more durable (in my opinion). If I expand to multiple kennels I will be buying more of the doc bob kennels as you can share interior walls and just buy an additional gate (ie. to make 4 kennels you'd buy 3 doc bob kennels and an additional gate).