Mainline is awesome but probably not an ideal for a new grower. (I top and super crop and have Scrog'd). But really it all depends on your goals and timelines. Sow to harvest is a fairly long time, If you learn cloning then this shortens the process by a fair margin and gives a better yield.
Do what your comfortable with and experiment on each plant a different style. 9 FEMALE plants under a 4 x 4 under a 600W is fine, so don't be afraid to throw a few more in there (you can always throw the males and the runts out).
Learn to clone. It will save you allot of money, you will yield more and better product and you will yield more often.