There are many types of Tail Poi and many things to consider when buying them. 

Let’s break the Poi down into several areas and look at each one in isolation: 

Ball – This can made from many materials including a tennis ball, bean bag, foam or rubber. They all have different properties and can make the Poi swing in a variety of ways. The main to thing to consider is if you hit yourself, will it hurt! The only way to see which is best for you is to try. 

Tail –These come in all lengths, sizes and colour. Some Poi have detachable tails which are useful for practicing (If learning a new move it can make tangles more frustrating especially if one poi ball hits the tail of the other). If using fabric that glows under UV light you will get an effect similar to a flame following a comet. Tails can add to the visual effect for black light (UV) performances or spinning in the sun for your friends.

Cord-This can be a cord, chain or wire. Some Poi have an adjustable cord or sometimes you can buy a specific length. Everybody is unique, so it will be trail and error to find which will suit you the best. 

Handle-Most Poi have the "two finger" handle which is made of woven nylon fabric. The handle will probably rub the fingers for beginners until the skin toughens up.

All Poi handle, feel and behave in different ways. Which is the best only you can decide?