Carvel planking: Stainless bolts or trunnels

Am building 75' all wood schooner. I'll be planking in about 3 weeks. Wood species (ribs and carvel planks) is southeast Asia Takien Tong, similar to many mahogonies.
An aspect of this part of the world is that it is very difficult and expensive to import some things to build a boat that are ideal (e.g. silicone bronze through bolts). So, I face using either stainless 316 lag or through bolts, or trunnels (tree nails.....big pegs made from a very hard wood). The trunnel option is attractive from a cost and availability standpoint, and some builders suggest 25 years from them, given proper maintenance. Not sure what to do after they begin to rot, but I'll be in a bowling league or something by then. I'm leaning towards 316 through bolts. THe heads won't be exposed to sea water except what might leach through the VERY tight grain of this species of wood, or perhaps the errant leak around a plug, etc. Is this significant? Barring using bronze, what are anyone's thoughts on plank fasteners (2"x8" nominal).
Thanks
Scott

 

If you search this forume you'll find that stainless is only good when it's in air, not when it's inside wood.
I think wood trunnels is your best choice, or galvanized steel.