That's more of a gap that I would want...  the Freaks do indeed handle a huge range, but like any sail they're the most fun when you have the right amount of power.

I've been using 6.3 / 5.5 / 4.7 for about 6 years now (155 lbs) and am very happy with that spread.  (and just one boom, one base and two masts for them)

Really depends on what your wind range is and how much you want to spend.   Will you really need a 4.7 often?  Maybe a 5.0 would be better with the 6.0?    Do you already have a set of sails that you're replacing?  Maybe replace just your most-used sail with a freak first to see how you get along with them  :-)

Drew

Linda, go for the 6.0 UL, then it won't be too big. If you've been sailing 4.7 before with that board and the board didn't feel to big, then I'd suggest a 5.3 (5.5 is a bit too close I think, in those light winds you'll be using the 6.0) and a 4.7 to go with the 6.0. UL's as well. The 5.3 is really really sweet.

Aim for a quiver!

A: 6.3, 5.5, 4.7
B: 6.3, 5.3, 4.7 or 4.5
Remember to change fin size.

Mast
If you have 430 top and bottom and add a 400 top instead, you get a 415 mast

Now you haven't mentioned anything on what conditions you sail in and/or the most common conditions ?

I would seriously reconsider getting the 4.7 (it IS a great sail) but unless you have the other sizes already you will need an other board with lower volume if it blows for a 4.7 as it will not be comfortable with your weight on a 92L

But I agree with the other on thinking ahead and plan a quiver
If you already bought the 430 mast you could start from there - the smallest to fit that is the 5.5 and to get the largest manageble gap then it would be the 6.3 (or stick with the 6.0 as that will fit better if you want the 6.7 which also fit the 430)
And then go for a 5.0 and 4.5 that both fit a 400 mast

Personally I have the 6.7-6.0-5.3-4.7-4.2 quiver which in my opinion have the nicest spread and cover from 8-18 m/s
But a minimalist quiver could be the following two option (at your weight you would need smaller sails as well if you live in a windy place)
6.7-5.8-5.0 (the 5.0 could work with the 415 combo) if you live in a lower wind area or
6.3-5.5-5.0-4.5 if it a bit more windy
Note that in the smaller sizes you can better get away a mast with a lower carbon content (cheaper)

Or the 6.0 - 5.3 - 4.7
And if you want a larger sail the 6.7

I sail in miami, Florida, which is usually lighter winds.. this is my first small board, been sailing a formula (which I adore) but knew I needed a small board for those windy days that I'm sitting on the beach watching others sail..and wanted to to it to the waves..I really don't have anything "good" for this board yet, as my 4.7 is a chinook powerglide which was my sail I used to learn on. I bought the 97% carbon mast, if I would have known it was the classic that swapped the bottom I would have gone for that instead because that was one of the things that interested be in the masts but just didn't take the time to ask.. So I have money for now to buy one new sail, maybe a 2nd used one just dont know which one to go with first.

Then you have an excellent mast to build from

When talking about SuperFreaks I wouldn't hesitate buying 2'nd hand as they are bombproof. But if you go for a 6.0 you need to buy from new as this size it was introduced this fall.

If you go for the 6.0 you could try to find a used 5.3 and 4.7 (they both fit a 400 mast)
And then get a cheap(-er) 400 that you then can change at a later stage. As mentioned the carbon content isn't as important in the smaller sizes,

Or go for a used 5.8 and used 5.0 and the cheaper 400 mast and you have a nice combo.

The only one who can decide what to go for is you

(I use a 5.8 with a 99L JP FSW and that is a sweet combo - see the avatar)