If you are going to use the bulhead as foot rest, you need to put it at a comfortable angel for your feet. if you want adjustable footrests or a rudder with pedals make it vertical.
If you do make it a footrest, make sure you make it strong enough, because if you stick your bow into the sand while surfing, you will put a lot of pressure on it, and if the bulkhead breaks you could end up with you feet jammed in the bow and the rest of you below deck, not good if you want to live.
JohnK