Can't really think of much off the top of my head. Sakai Takayuki make one that's about 700g and made of white 2 but it's only 210x75mm. Another option would be getting one custom made from Moritaka.
Out of interest, what are you cutting with it? I'd like to pick up a #22 but for it's intended purpose I'd rather abuse a $20 cleaver than a $300+ one.
Cheers,
Josh