If they are anything like the figure skate boots, there are different levels of support on the ankles. The stiffer the support, the higher level the skater. So you don't want something that like that if you are a beginner. Riedell has a decent beginner figure skate boot, and I believe they make roller skate boots, too. I would start with that brand.
With figure skates, not all blades are created equal -- far from. Stock blades don't land the high jumps. They okay for beginners or for recreational skaters, but not for skaters actually wanting to learn moves and jumps. I'd assume the same is true with roller skate wheels.