Source for 6 inch F5 mirror?

I'm looking for a replacement mirror in this size. How do the discovery mirrors stack up? I know they say 'diffraction limited' which might be 1/4 wave. I would like a little better than that! Are they?

I just want my telescope to be fairly decent without breaking the bank. It probably won't be my main scope in the future but it will serve as a travel scope for camping, etc. I'm looking to spend around 200 clams. Do I have any other options but Discovery?

Thanks for any replies,
Mark

I have one from University Optics (just ask--they aren't listed) and it is much better than 1/4 wave. It was ~$190 when I bought it.