Cpt. Brown, I like your take on the Spiders. I have been updating the same Regiment, but I like your take very much, especially the cammo and the forage caps. One really key component I think you should consider is the facial tatoos, which are something I always remembered from when they came out.
As for the wings on the side of the company number, I'd definately add them.
Here's a shot of how I tried to do the tatoos (guy on the right). With your painting chops you could definately take it a step farther.