preamp or compression

[mentil69]

Hi Im planning on buying either a really good 1 channel preamp to get a warmer vocal tone, an RNC, or a mutichannel preamp for drums. My drums go through my Mackie 1402 VLZ mixer with XDR preamps, and into a yamaha 2816. I was wondering, with this setup, what will i get the most benefit out of buying? Any input woul be appreciated. also, how much better would the compression out of an RNC sound than the compression out of my aw2816, if at all?