I second Jenn. Please do avoid breeding or supporting breeding.
http://cavyspirit.com/breeding.htm http://cavyspirit.com/hollister.htm http://cavyspirit.com/petstores.htm http://www.guinealynx.com/breeding.html
There are over 2,000 recorded (there are a lot more that aren't reported) homeless cavies as of March 2006 in the US alone (according to petfinder.com). Breeding is also very dangerous, 1 in 5 sow dies giving birth. There are also genetic abnormalities that occur because of inbreeding or breeding the wrong breeds together resulting in lethals.
http://www.cavycages.com/forum/showthread.php?t=4190
Adoption is worth the effort. Check out the adoption forum on this forum, on
www.guinealynx.com, on
www.pigloo.net, check out
www.petfinder.com, you local humane society, your local newspaper,
http://cavyrescue.com/,
http://www.craigslist.org/. Be patient and you will be able to save a wonderful pig.
As far as cubes inside the coro, I thought this was a good idea too at one point. It just doesn't work well. Poops get wedged up against, under, and in them. And then you can't make a connected stand for it out of cubes (which isn't a big deal if you cage is on the floor or table, but mine isn't.)