Thank you for the input Mike.
I don't know about the stringers necessarily "lasting" 29 years. The originals are still in the boat, but as far as when things failed and they began to rot...that's a different story. This is obviously a known issue with these boats, mainly due to a very poor stringer/floor design, poor materials, and sometimes shoddy craftsmanship from the factory.
That said, there are legitimate reasons they no longer use lumber in making these ski boats nowadays.

If there is a viable composite replacement, I am still leaning towards going that route. I figured I will have the entire thing apart anyway and will be taking my time with the job. I'd like to use the best materials I can while I have it opened up. Please don't get me wrong though...it's not that I'm completely opposed to wood, after all I am a carpenter by trade. I'd just rather use something else if I can maintain the structural integrity of the boat, eliminate ANY possibility of future rot, and eventually help with the resale value a bit. I think that "upgraded composite stringers" would be an easier sell than "new wood stringers done the right way", IMO.

Again, I'm not in any rush to jump into this, and if wood wins out...so be it! I'm doing lots of homework, compiling all the data, and even more importantly, the opinions of those who have way more knowledge than myself! I will make sure to put your check mark in the "WOOD" column. We'll see what the final tally comes to in a few month.

In the meantime, if anyone has them, I'd still like to get an idea of the dimensions of the boards I'll need.