Natasqi, I have also had the same question and often finding the right kind of hoop for you style can be the bane of a hoopers existence.
This is what I have learnt so far:
Rhythmic Gymnastics: Rhythmic Gymnasts need to use a regulation hoop so this is the easiest one to work out. You can have a look at some of them on this web site
www.amco.com.au. These hoops are a lot smaller than your average dance hoop and the actual diameter of the ‘tube’ is a lot smaller. The nice thing about these though is that they are quite ridged and heavy.
Circus: Circus hula-hoopers use all kinds of different hoops, mostly it comes down the where they learnt their skills and what style of hooping they do.
If you look at people that have a style like the girls in cirque de solei then they will usually have some thing like a rhythmic gymnastic hoops because that is usually where they first started to learn their skills.
If you look at an ameture or youth circus hula-hooper they usually have hoops similar to the hoop dance ones because you can make them yourself. But they are usually a bit smaller. Also lots of circus hula hoopers use these for training because they don’t hurt as much when they hit you.
If you look at circus hula hoopers that do lots of multi hoop splits you will probably find the will have one of two things, the first being aluminium hoops that are skinny and pretty heavy. The down side of these are they are really LOUD when they hit together, The Second being hoops that are similar to the hoop dance ones but again smaller and usually stiffer.
Lastly if you look at the hoopers when they do ‘stacks’ of heaps and heaps of hoops that are some times thrown on, they will usually use really really light hoops because once you have 10 or so going it can get really heavy. Also if you see somebody hula hooping heaps and heaps of hoops that are all going at the same time from the floor to the top of their hands that is called a slinky and is actually a stack of hoops that is threaded together.
Wow that was longer than I thought it would be. I found all of this while searching for the perfect hoops for my style. I think I have found them but am still saving up my pennies to get a matching set.
Currently I use a set of 8 hoops that are made from high density poly pipe. They come roughly up to my hip bone when I rest them on the floor; I have found that this tends to be the standard sizing for circus hula hoopers.
The new hoops I’m going to be making will heavy duty hot water irrigation pipe this was a recommendation from a trainer at the Fruit Flys Circus. The reason why this stuff is really good is that is really stiff and not flexi, this is a must for doing splitting which is what I’m working on, because other wise all of the effort you put in to moving the hoops gets absorbed into the bending of the hoop. Unfortunately this kind of piping is kind of hard to track down.