Go nuts and get it all done in one shot.
It's a little bit of overkill but it's all right there, and ready to view. Anything blocked of view is just what is being upgraded anyways.
If you just want a couple of gauges, you might still be able to get away with an stealthy installation on the column. It's function that should dictate your preference of what gauges to install. Follow what the other guys mentioned above, this was just to illustrate what I wanted to try because I had never really seen it done before. I will have to install a WB 02 unit soon; SHOULD but haven't as of yet.
Oh, those are tie strap left overs used to keep the gauges from rotating while I was determining fitment to keep them tight in their bunks (2" PVC pipe).