mcrt said..
The Naish wingsurfer V1 was considered softie and low power even compared to other V1's.
The foil is old design,this sport has evolved fast.
The board is big for winging,but good size to keep as a SUP foiler maybe.
For 80kg and 12-25 kt i would say:
4.5m Wing
1200-1500 Med HA foil
90 liter board
If you can afford it best thing would be to look for a store package including all three,and sell what you have ASAP.
As Hilly says your expectations of what you will get for your gear might be optimistic.
Upgrading just one thing...i would sell wing first,foil second,board third.
Sorry if this sounds negative,just trying to be realistic,it is an expensive sport.Most guys here (me included) have thrown lots of money into the water :)
agree ... sort out the power 'source' first, i.e. the wing, then the flight surfaces (i.e. the foil) then the board ... good luck! It will be a fun journey investing and enjoying new gear and skills afforded by the higher performance kit