Nightforce probably makes the lightest type mount you are looking for and Badger is probably the cheapest new. The only other companies that I'm familiar with that make what you are looking for are Geissele, Spuhr, and a surprise to me Primary Arms. I only see it available in a clear anodized finish though.
Primary Arms 30mm PLx Cantilever Mount 2.04" - Clear Anodized
DetailsAs part of the PLx line, these 30mm mounts meet the exacting demands of professional use, offering impeccable craftsmanship and advanced features.PLx Scope Mounts are 100% US-made from 7075 Aluminum and feature grade 12.9 steel hardware with a proprietary Electroless Nickel coating for...
www.primaryarms.com