Russian Birch Plywood For Interior ?

[luso]

Thank you guys for all your help and suggestions in the past.
We have a 52' steel hull sail boat that we are completely redoing one project at a time. At the moment we are rebuilding the interior, the inside is completely empty and we have been researching some of the woods that are available and affordable which we will be using.
We thought to use 1/4 plywood for the ceiling, 1/2 for the sides and 3/4 for the bulkheads.
After checking on prices between the marine okoume and the russian birch, the birch is 50% cheaper and also has more plys, but not much information out there for it. The okoume on the other hand is more popular but we are not sure of the quality. Any sugestions Please
Thank you, Luso