Yep--to find what works best for you, you'll have to experiment a bit. Not take 3 or 5 shots, but actually tune and shoot--may take a little time, but will pay off. There are no "one size fits all" answers.
A general suggestion would be 10 strands of Dynaflight '97 or 10-12 strands of 8125. You might get a small increase in speed, depending on several variables--how your nocks fit your string now, how they fit the new string, if your release changes with the new string, etc. Won't be anything earth-shattering performance-wise, but it should change the feel (you might like it, might not).
Good luck, have fun, and keep good notes.
Chad