I think 8oz is pushing it. I think 10 is the lowest I could stomach going. Even though a converter would bring it up to 10...the padding is important too and I would think 10oz would be much better all around as a glove.
That's still only 11-12 oz. only (with the converters). Moreover the converters will balance the gloves (since naturally these are a bit front loaded), so you would hardly notice those 1-2 oz. difference.