I would definitely not go for non-underwired. It just doesn't offer that support, or 'oomf'... if that's even a word? Anyway, stick with underwired, or else you'll end up with saggy boobs! :-)
As mentioned, Freya is good. I always shop at www.bravissimo.co.uk, as they have a great collection and stock up to an L! (I know, I never knew that size existed either).
I have tried those "total support" ones from M&S (I'm 34G) but they just don't seem to offer the support that the wired ones give, and I'm always worried what the effects of constant wearing would result in.
However, this is from someone that wears a bra 24/7... even to bed!
My opinion - stick with the wire :-)