there's a trick at bsolutions for rendering a wireframe animation - I believe you can set it up to render this way at your large resolution to get a wireframe render (create a movie that's 1 frame long, I think was the trick... been a long time since I've done this...)

http://www.bsmooth.de/BSolutions/#Render

you'll still need to compoiste the large wireframe 'render' with your full rendered image using a third-party image editor, but at least your wireframe render will be at a better resolution for doing so.

______________________________________________________________________________________

Check out my Elemental Hexagons deck, created with Photoshop, Bryce, MojoWorld, and Poser