New amp or new cd player?

With which will i see a bigger improvement in my sound. I have a Mcintosh MA6450 integrated, Gallo 3.1 speakers, and an onkyo dv-sp404 dvd/cd player. Monster interconnects, and transparent music wave speaker cable.

Obviously my weakest link is the onkyo dvd player as a cd player. I was thinking about upgrading it to a naim cd 5i or classe cdp-102. However, I also know that my amp could be more powerful as it is 100wpc into 4ohms, but only 50/75? wpc in to my 8ohm gallo 3.1's.

My question is.. with which change will i see a greater improvemt? In my currently living sitatuon, the mcintosh easily powers my speakers louder than i can play them for an extended amount of time, but will more power equate to more bass? I was thinking about the Classe cap-2100, but will this result in more bass, and better imaging/soundstage/etc, or simply the ability to play louder, which i dont really need.

As for the cd player, I have a hard time believing a cd player can make THAT big of a difference (I am new to this high end audio stuff), although I know they must because all I have read on here and other places around the internet. Although I have also read that a decent cdp used as a transport, and a dac such as the bel canto dac 2, sound nearly as good as some of the very good cd players out there.

So.. long story short.. would i see a bigger improvement if i keep the onkyo as my cdp, and upgrade the amp, or if i keep the mac 6450 and upgrade the cdp?

James