How old are you?
Do you play other sport? (baseball, hockey)
Reason I ask:
If your swing is still developing and your not a senior and play (or had played) other sports then I'd go with the stiffer flex. Logic says that once you figure out a proper delivery you're club head speed should increase; assuming your naturally athletic and young (ish).
Lots of variables, but those were the two points i most considered when isold clubs to customers, that where just starting out.
I played on an empty golf course today. I played a 6 hole stretch using just my 6i-LW. Left my longer clubs in the bag. The 6 hole stretch had 2 par 5s. I hit my 6i on average 135 yards carry. Out of those 9 clubs, I used 5 of them.
While doing this, I also played my regular game using all my clubs. I played 2 ball. I was one stroke better using only the shorter clubs.
Going to do the same short bag thing tomorrow for a 9 hole score.