I understand that there is nothing wrong with crutchfield. But they OVERCHARGE for everything. You can go to a store or shop else were online to find a better price then they give you.
Check this out
crutchfield - 349.99
that is why i never buy from them.
About the hacking of your original speaker wire you should never do that. RUN a new wire and keep the existing one there and it never has to be cut. It saves your car for resale value.
Quite the price difference, makes one wonder why? Did you happen to see or know that what you are getting from carstereoworld.com may be a refurbished unit ?
Anyway back on to the subject...AKPsiMC03, If you have the money, which is always a factor. and depending what kind of system you are looking for of course, you could replace all speakers as you suggested, and get a 4 channel amp that can run them all...You have nothing a good quality (Alpine, Fosgate) 4 channel amp can't handle, plus it makes it easy to upgrade later on if you wanted..
The first and main factor in any good system is the head unit.. so pick that carefully and understand all that you want, and may want to do..That way when it is time to upgrade to better, more or even adding a sub to it all,, the deck will not even be an issue.
Good Luck with it all and hope it sounds well