Given your supplies on hand, I'd choose Bullseye. It fills the case nicely, burns completely, and gives satisfying velocities at reasonable pressures. Unique has never measured as well for me, and you need more for each round as well (since it's a slower powder).

If you want to try something else, I've had great luck with Accurate #2. To motivate you even more, Powder Valley's selling 5 lb jugs for $65. (Of course, they also have 8 lb jugs of Bullseye and Unique for $96...)