I dont really think the eliminator is any better than a hybrid. Your still stuck with the compromised stock manifold etc, so its not really as good as you think it should be. the housings also much more restrictive than a "proper" GT28 so it doesnt make the numbers.
Mark also had two of them fail, so i'm not sure what that says about their reliaibility...
250 is easily attainable with a hybridised K03, and with the right bits you'll probably get upto around 280ish.
Speak to beachbuggy on here. He does a wide range of hybrid options at various price points.