The dynapoints are probably middle ground in the power department... if you want something real low power and very quiet you can shoot out of your 10/22, check out CCI CB Longs - there's no powder in the casing, just the primer. velocities are around 600fps I think, and they're only a bit louder than a strong pellet gun out of my 20" barrel - a bit more from stock. The problem is they're hard to find and more expensive. Also easily confused with CCI CB Shorts, which are in the .22 short case, and, while they'll fire out of a 10/22 just fine, they won't feed out of a stock magazine.
If you're feeling brave, venture over to
www.rimfirecentral.com - they're a forum pretty well dedicated to the 10/22 and after that all things rimfire, but I can only stand so much because people are always talking about the same damn thing that they could just use the search feature for. Lots of useful information if you can wade through the n00bs asking "what barrel is best" and other such stuff. Many things just come down to personal preference.