The design objectives are completely different. A longer windsurfboard is still quicker to get
gliding and often planing as a short and wide board. With a wingfoil, you simply want to get as quick as posible in that gliding phase, because then your foil lifts you out.
I,m 95-98kg depebning on time of year and have 3boards that I can wing on.My KT5.4x56l with all the stuff going on in the bottom. A bit longer and thinner as most boards of that volume, but due the extra length quicker on the foil as short/wide/thick boards as the Duotone with 75l for example.
Beause it is less wide you don,t have to stand in an offset and because its thinner you get a better /more direct feel of the foil.
AK Phazer5.6x27x90l..still relative long for a traditional board and very quick to get going but still significant slower to get up as the Sunova Carver 6.2x20x 95l. More as 5l does. The 6.2x20 Carver feels due the les width more maneuvrable as the 5.6x27AK.
Sunova Casey DW Elite 7.6x23x137l. I bought this to learn to DW, but i,m shocked by how good of a crossover it is. Yes you feel more swingweight as with the AK5.6, but I can still, jibe, tack, ride waves etc with it.
To ad a very intersting DW style board to the list that I have seen on the Boot-expo in Dusseldorf IRL and is now launched: Sab.
sabfoil.com/en/products/torpedo-100lIn europe E1650 for a full carbon/pvc reinforcement under the deck with a Bag sounds like a very good deal. The board looked very well made.