new transom/engine beds 23 Tsunami

[bigeasy1]

I just finished building and installing a new transom on my Tsunami project.I used two 3/4 pieces of marine fir plywood glued together with epoxy.

I laid up a couple layers of 1708 on the inside of the skin,then we glued in the plywood,and then we put three layers of 1708 on the inside face of the plywood.

The final thickness is approximately 2-1/8 inches,which is within the requirements for the Mercruiser (2 to 2-1/4).
I now have to tie the stringers back in,and replace the engine beds,(and eventually cut out the i.o. drive hole).

I have a question regarding the engine beds(short type of stringer)
What is the best wood to use?,.
iv'e thought of fir,or spruce,and even mahogany or cedar.I also gave some thought to pressure treated,and i know that the glass may not adhere to it,but the glass basically is just keeping them in place,so that may not be an issue.

I plan to put good limber holes in them,but also want to use something that will last.

The following pictures may show them better. In the last picture, "you can see where the engine beds have to be built.I have marked them in black lines."
Any reccomendations or thoughts would be appreciated.
Thanks all.