Seeds for bamboo are available only when a particular species flowers...which happens unpredictably in cycles of 20-150 years. That's why people wanting bamboo typically buy a division of an existing plant. You can find some bamboo seeds available on eBay. However, it is illegal to bring in bamboo seeds from outside the U.S. without a special permit and a quarantine period, so it's recommended you stick with U.S. sellers. In addition, although bamboo grows quickly once established, bamboo grown from seed may take 3-5 years before it reaches your height. Finally, since you appear to be in MN -- and I'm someone who fled from the Twin Cities years ago -- I can tell you that it is unlikely you will be able to grow any species from seed, plant it outside and have it survive your winter. I'm not trying to discourage you in your quest to grow bamboo from seed...just calibrating expectations.

I second kudzu9's comments. Growing from seed can be fun, but you'll have to protect the plant during winters (bring it indoors maybe), and it will be a few years before it's a reasonable size. If you wanted an oak tree in your yard, would you plant an acorn, or buy a sapling that's a few years old already? Buying a bamboo division is the way to go. Even if you start from bare rhizome (which can be tricky), you'll still be a few years ahead of a seed-grown bamboo.

You may be able to get a free division (a dug section) of a plant from somebody who's growing it in your area. Many people who have bamboo in their yard are really eager for somebody to help them control it by digging some up.

If you are looking for a quick screen, visit some local outlets to see what they have for your area.