there are countless number of activities or machines that we can do, so there would be no way to have them all listed. A custom activity would be a nice option, I can pass this on to see if anything can be done.
In the meantime, I suggest finding the closest thing to what you are doing and adjusting the to to match the actual calories burned. Most machine will tell you the calories burned. As far as the classes, you'd have to have a HR monitor/calorie counter on you to get an accurate burn. If you don't have one, it may be hard to calculate since everyone burns calories at a different rate.