Check Amazon also. I bought the bigger of my pots there.
Make sure and read the reviews though. I wanted to make sure it was a heavy enough pot and had a heavy bottom. I read the reviews and a home brewer had posted there. His concerns were the same as mine and he posted about the thick bottom and quality of the pot.
I bought it.
I don't have a lot of exposure to different software, but beersmith is great. Easy to import recipes, does every conversion you want, you can keep notes. On and on.
If you want to try beersmith, I think you get 20 or 30 days use before you have to buy it.
Download it and give it a try.