here is the BOM of my efoil, which was designed to be simple to make and cheap, but sill working very well (very efficient, 24 km/H at 1200W) :
For more autonomy, 20A LIPO batteries
For more performance, change to Veloce L or MT.
I also bought a folding propeller (EML store) for 150 €, to be tried in waves soon.
Do not hesitate if you have any questions,
(detailed pictures of the build in this post : First easy and low cost build in France La Grande Motte )