I have read till i am blue in the face and everyone states something different. Should i be designing in CMYK or RGB?
There is no one size fits all answer to this question. It depends on the situation, and the intended goals for the particular project.
If the goal is to get every bit of the color that the printer is capable of delivering on the media being used, the proper answer is to design in RGB, using a relatively large Working Space, such as Adobe 1998.
If the goal is color consistency with other types of print, then designing in CMYK, using SWOP or Gracol Working Spaces would be the means to get there.
In the plot below, I am comparing the gamuts of:
Adobe 1998 - RGB
US Web Coated SWOP v2
An HP Latex 360 printer, printing onto IJ180C cast vinyl (a custom output profile)
As you can see, the printer's profile dwarfs that of SWOP, and is mostly contained inside of Adobe 1998 (you can better see this in the 3D plot comparison). Designing in CMYK SWOP will restrict the colors in the file to those inside of the red boundary, and if the color is not in the file, then the printer should not be printing it.