logitech z5500 or PA speakers

I have about $400 (could go to 500 but prefer not to) to spend on a speaker set

i as looking at either the logitech z-5500 speakers

or

probaly these speakers

http://cgi.ebay.com.au/ws/eBayISAPI....ayphotohosting

plus and amplifer (can annyone suggest one that would power these speakers for quite cheap, it would also need to power a sub that i will save up for)

i dont know alot about speakers an amplifiers, and thats why im asking
thanks for your time

That's kinda like asking us wether you should get a Smart Car of a big honkin' pickup truck.