P.S. One way to get a wide variety of known heirlooms to trial is to join seed swaps.
Buy or save many seeds of one known variety that you think will be popular. Then join a swap and offer 10 seeds of your variety for 10 seeds of another variety, and hope that a dozen people are interested.
Or if you are offering, someone may offer seeds in return for postage.
Or look for a local "seed library" and check out a few varieties. They may ask you to grow some in isolation (or bagged) and "return" the seeds next fall, multiplied.
http://www.seedlibrarian.com/
