@umbra21 - It's true that you need to make sure that you have a unicycle that's going to be comfortable for you to use and that isn't going to hurt your muscles or anything like that.
But you also have to be safe. Particularly if you are planning to ride on the road.
The unicycle has to be one of the most dangerous vehicles to use on the road, since it has so little room for lights and it's so small, it would be difficult to see on the road.
The one advantage is that when you are sitting on the unicycle you are sitting quite high, so if you wear good reflective gear, you'll be visible. So, if you're planning to go on the road, you'll need to make sure that you've got a unicycle that's high enough for that to happen.