You’ll find it difficult to get around these limits. Account creation restrictions are built with average use cases in mind – when you have a use case that doesn’t fit that, you just have to be patient and work through it in a way that does not circumvent the limits or otherwise go against the spirit or word of the TOS. That might mean it takes a lot of time and waiting before getting all the accounts registered that you want.
Of course, while you’re creating accounts, make sure you’re following all the rules around name-squatting as well: https://support.twitter.com/entries/18370