I feel like an idiot... I did not even think about getting an 11x14 with a reducing back. That might be what I'll do.
How much do 11x14s normally weigh?
The thing here is, most vintage 11x14 cameras, even a light one like a Kodak 2d style are heavy in comparison to an 8x10. There are many more lightweight choices in 8x10, both vintage and modern construction.