Looking into RO/DI systems, am I on the right track?

[mandyplo]

I am in on the group buy already, now im just deciding what to get

I also live 30 mins from the US border and usually ship my online purchases to the border anyways, so I'll just do that again this time n get me some free shippin'

I am also looking at getting NP reducing biopellets/biopellet reactor and a pump.
While I'm at it, should I get one of the 2 cartridge reactors for some Carbon or GFO? I don't know a whole lot about carbon or GFO so im going to read up on it right after I post this, but I value anyones personal experiences if you wish to share them.

Edit: Okay just read up a little bit about GFO and Carbon.. By the sounds of it, the BRS dual reactor for GFO and Carbon sounds like a good idea, but does that mean I still have to buy a separate reactor for NP reducing biopellets? Or do you even need to run NP reducing biopellets with Carbon and GFO? Thanks in advance for opinions/experiences.