If you want to increase your strength and flexibility you should definitely consider getting an anti gravity yoga swing. You can learn about one of the best directly from the source Omni Gym Yoga Swing.
The newest model is an YogaSwing Deluxe. It is the best model I know about. You can get the basic model for a little bit less.
You’ll see something called an Rockit Stand on the page as well. You don’t need this to use a yoga swing. It’s definitely a great stand to have if you can afford it; Keep in mind it’s the most expensive piece on the site and you don’t have to have it.