Ken has given you some really good feedback here.
I'm not familiar with Gun sails, so I cannot give you much guidance on which of the Gun sails will suit you the best.
At your level, I would think that the simpler no cam Rapid might be the better choice, but free ride sails tend to be pretty flat and may not have real good low wind power.
If the Rapid is indeed a "free race no cam" (similar to the Sailworks Retro) then it will have excellent low wind power and a wide range of use.
As far as your first solution vs your 2nd solution, that's going to depend alot on how much of your sailing is in the 12-16 knot range.
Your 9.5 m2 will be for max early planing in < 12 knots.
At 12 knots you have to make a choice on 8.5 or 8.0 m2. I like the 8.5 solution a little
better as this gives you more power in this wind range, which can be the difference between planing all the time or not planing much at all.
Sure you can re rig your 9.5m2 and you might have too much power in the gusts, so 8.5
seems a very good choice.
But dropping from 8.0 to 6.3 leaves you with a really big hole in the area where when your skills are fully developed you are going to want to be nicely powered as much of the time as possible.
I think the 2nd option (9.5/8.6/7.5/6.3/5.4) is probably going to give you the most quality time on the water.
I also agree with Ken that you will soon want a smaller board for anything above 14 knots.
Hope this helps,