Spark Plug wires

I figured the next "small" upgrade for my Silverado would be some new spark plug wires. And of course, this raised a few questions.

1. Should I get some new spark plugs aswell? (If yes, a suggestion please)
2. Check these out. What do you think?
http://www.stylinconcepts.com/part.aspx/partID/13151/PartFamilyID/561/SubcategoryID/244/CategoryID/27
3. What exactly are the advantages/disadvantages of this mod?
4. How easy is the installation?

Thanks for the help.

ive been told that plug wires wont make any more power. dont change them unless they are bad. thats what i have been told.

I've herad otherwise. People upgrade to MSD 8.5mm wires all the time. THey're about $80 a set. I'm doing this with a set of AC Delto Iridium plugs shortly to help stop the pinging in my truck.