Your board size is about right in my opinion. Others will say to go smaller to start with, but I can still remember hopping on my 130ltr after a year on a 165ltr. It was like a postage stamp. I would always suggest the go big approach to start with.
Assuming flat water and average size of say 80kg, I would suggest a 6.5m sail. This will be too big when it really gets up, but with a big board you wouldn't be in control even with a smaller sail. So to start with don't bother trying to kill yourself in a howler.
6.5m will be too small in light winds, but you will still be able to sail around getting your balance and trying those tacks and such.
When you are comfortably in the harness and straps and planing around, you will need a larger sail for those lighter days.
For the strong days you will need to think about a smaller sail and a smaller board as a set.
That's my 10cents worth anyway
