I got that Iron Oxide Plugin, its insanely dope, you can completely change the shape of drums, strings, brass, anything.. but concerning sounds in Logic:
If you cant be bothered to take time to feel Logic out and really mess about with it, purchase some new Vst's and whatnot, although this is the expensive rout...
Logic is extremely powerful though and has some amazing plugins that come with it as well, if you can be bothered to tweak the sounds using various plugins then you can make pretty much any sound any way fat, thin, big bass.. absolutely anything, so i would take the time to mess around with Logic first before buying other stuff.
and say you get a plugin to make the brass, bass, drums sound perfect to your liking, you can save the preset so you dont have to do it everytime you want to make a beat.
Think about it man, its not bout what you got its how you use it, why you think people can make insane stuff with Fruity Loops, cos they know their shit inside out, whatever they can do in Fruity, you will most probably be able to do 100x better in Logic if you learn you DAW like they have
Cm