If your looking for good speed and penetration then go with a good carbon arrow in the 7-8 gpi category.You will definately gain some speed with the lighter arrow.
I was also wondering what kinda rest you are using.With a 26 inch draw and a 28.5 inch arrow.Even if you take your Bass Pro Carbon Furys and cut a few inches off the end will give you some extra speed.Leave about an inch in front of the riser.
A lighter arrow will definately give you more speed ,yet a heavier arrow will give you more forgiveness.Go with something in-between and have the best of both worlds.