As others have said, I'd recommend visiting a dedicated running store. My local store has been incredibly helpful in picking the right shoe. They looked at my foot shape, arch, gait, posture, running habits, etc.
After much trial and error, I bought a pair of Altra Superiors and never looked back. The shoe works for me for several reasons:
-Wide toe box
-Zero drop (heel and toes are the same distance from the ground)
-Removable rock guard (a thin plastic insert that fits between the sole and insole) that allows me to run on both road and trail
-Integrated gaiter hookups (a feature on many Altra models, but may be helpful given your sandy/wet terrain)
-Agressive tread
All of the above makes it a good shoe for me. Hope you find one that works for you.