Severne Blade & S2 range (on SDM)

[millen]

Hi,

I contemplate buying a set of severne sails.
4,2 - 4,7 - 5,3 - 5.8 - blade 06
and maybe a 6,4 s2 06.
Now my both questions:
1. What range can you advise me?? Is it necassary to buy 5 or is one size not essential?
I´m sailing them on lakes and flatwater.
I´m surfing not very long but I´m very motivated and want to improve my basics and want to start freestyling soon.
My weight is 70Kg and I have a f2 eliminator 115l and a f2 air&style 96l.
2. question
are the sails working with SDM masts? I have a north viper 100 430 and a fiberspar 400. I don´t want to buy a new mast.

I´m looking forward to your help.
cheers
Milli