Our advice for foil boards is go light but tough. You may be surprised at which ‘premier’ brands have had foil mount boxes rip out, or take on water and start to weep.
Recommend looking for decent ding resistance in a board, making a good balance between durability and lightness. Even more importantly, you are looking for a bulletproof foil mount box. Construction should include extra care for mounting a high density foam box with the stringers routed through it. The boards we carry have solid, well-built foil mounts.
Your next concern is getting the right volume for your skill level, activity and conditions. For winging start with +20L over your weight in kilograms, for prone about half your weight in KG is a good starting area.
Other than a tough foil box and appropriate volume, the other major concern is the ability of the board to bounce off the water, rather than edge and stick. Most newer boards have a scooped nose and rounded rails.