I am in this same boat. Over time I have accumulated 38,401 in Empire bounty vouchers and would really like to turn them in. I also had about 16k in Alliance vouchers, but was fortunate enough to find a couple Alliance stations in Ross 210, an independent system.
I was hoping to find an empire station not so far away in another independent system, but have had no luck. I am deep in Federation space, and the nearest Empire-controlled system is a good 50-70 Ly away. It will probably cost me what the vouchers are worth in fuel for my Viper. That or I'm going to master this fuel scoop.
Why the heck does the Viper use 10x the fuel that the Eagle does, anyway? The Viper only has 20% more mass. That makes no sense.