Fast, Wide Prime? {i.e. 28mm f1.8, 30mm f1.4, ...}

[ivy weddings]

My wife is happy with her fast 50mm and 85mm primes. But not I.

I love using a fast wide prime (for engagements, bridals, weddings, etc), and would love the 35mm f1.4 L - but don't want to drop quite that much right now on glass. Partly because we've worked with several Sigma EX primes and found great optical quality, I'm thinking of going a less-expensive-than-L route.

Would like input: I'm stuck between the following lenses-

-Canon 28mm f1.8 (personally think the build quality on canon mid-grade primes sucks)
-Sigma 30mm f1.4 (love the specs, but performance wide open?)
-Sigma 28mm f1.8.

I'm heavily weighing towards the last lens - because I've actually used a really old version of the first edition of this lens and it's killer nice.

Soo.... Anybody used any of these three? Or anybody want to give me a free 35mm f1.4 L? ;)

-Matt