My suggestion would definitely be to go with a shader based on a tile-able, free wood grain texture... and to have two versions for old and new Poser...

If you went the tiled texture route, you could have a version that just has the texture with diffuse and specular and perhaps an old school glossy node, for older Poser versions.

Then you could make a shader with BBGlossy and Matmatic, based on that script Snarly revised, over the top of the tileable texture, for newer Poser versions?

There is likely plenty better, free to use, seamless texture sites, than that one I linked to, I'm guessing...

Cheers