Increasing casting distance.

I want to increase my casting distance with light lures (1/16th oz),
using a spinning reel. I'm using a 5' 6" ML rod with a Symmetre 2000
reel and powerpro 10/2. I have 2 ideas. One is to spool my reel as
full as possible. The other is to switch to a longer rod (maybe 6'
6"). I suspect many of you will recommend the longer rod, if so I have
a question. Most 6' 6" rods seem to be rated M or higher. Will a M
action rod work with really light lures? Should I get a ML 6' 6" rod?
I was thinking of the Berkely Bionix (50$ at Walmart).

Thanks!

Chuck.