Good plugins for sounds and fx for pop and r&b

Hey,

I'm looking for good sounds that I can tweak, because I have worked a lot with the built in plugins of Logic Pro 9 and would like to move on from there, especially regarding drum sounds, and things like bass, keyboards and brass. Where do I go? I'm on a budget, so I can't buy a fancy hardware synth or keyboard, which I would have preferred doing. I would like these sounds to sound as professional as possible regardless... Finally, also what about nice sounding effects, like digital reverbs, compressors, delays et cetera. Where can I buy all these? Any suggestion is appreciated. It's fine if you drop some names, and if you explain these things a bit, even better. My music style is pop, r&b and hip hop.