remember it will cost you quite a bit to have them fitted if you buy online. In the town I work its common for a intuition mold to cost $50, if you need both shells stretching thats another $40, and you will still have no boot fit garentee so if you need more work in the future that will cost you too.
If you buy from a shop it may cost slightly more in teh first place but it will almost certainly be cheaper in the long run, and you will also have piece of mind that the boot will get swapped for you if it turns out its not the right boot for you.