Improving your studio monitoring environment is ALWAYS the best way to improve your recording quality. If you can't hear, the fancy toys make no real difference.
After that:
How To Achieve Pro Recording Quality
There is a dramatic over-emphasis on high end gear in my opinion.
Is Gear The Answer To Sound Quality Issues?
Lastly, if you are ready to dump some money on gear and you trust your studio monitoring, I'd start looking into developing your microphone palette.
Brandon