Dave,
I did a quick search looking for a longer screw for the type of clip in the thumbnail of your last post. I used a similar clips (found in Home Depot) to install a kitchen in our basement. If a longer screw is not available, I thought perhaps there is a special tool that will help with the installation.
Here is a link to what I found:
http://www.homedepot.com/buy/plumbin...ps-122796.html
Scroll down and read the one customer review - there is indeed a special screwdriver that sounds like it would make securing the clips much easier. It is an Elkay LK350 Extra Long Screwdriver:
http://www.faucetdepot.com/prod/Elka...iver-30962.asp
Dick