If that's your oppinion then you should either use a single coil on the speaker (which is rated at 200-500W) or get another speaker.
You'll get more power at 2Ω, but more power is not necessarily better. The 2Ω will be quite hard to drive, at some frequencies it will be much lower than 2Ω, a 4Ω load will probably give better quality but maybe not quite so loud. Are you driving the amp at it's full rated power?
If you want 350W out of that amp, you've bought the wrong components.