As the title states, I am hoping to install a new raid drive as the secondary drive?, I would put it as the primary but I don't want to have to go through windows 7 install procedure and activation again.

If I remember, you can choose where to install Steam, but not New Vegas. That will automatically install to your Steam folder.

I installed Steam on my D drive no problems, but didn't have a choice on where to install the game.

After installing New Vegas, I used this: http://supportwiki.steampowered.com/wiki/Moving_a_Steam_Installation to move my installation to another drive. Works!