I'm looking to buy an e-commerce package, like Miva.com or
MonsterCommerce.com, but I need one that does side-by-side comparisons
like what you find if you go to cdw.com, select "hardware > desktops",
"search all desktops", then check a few check boxes and click
"compare". Are there any out there?

hi severisth!

here you can buy a solution thats do exactly what you need to do..

http://www.x-cart.com/

but you must buy the "compare plugin" in order to enhace the system as
you need it..

http://www.x-cart.com/feature_comparison.html

hope to solve your problem!
Emiliano.
=)

Nice, that's the sort of thing I'm looking for! Thank you Emiliano.