Ok, I will give you my impressions as a new guy to this. I ordered both the DOP and POP kits from B&S. I found the DOP much easier to use than the Ziatype kit. Controlling the humidity for printing was a big problem for me, but then it might not be for you. I found contrast easier to control with ziatype but with DOP is not all that hard either. Specially if you use the restraining in developer technique and Sodium platinate as a contrast agent. I have printed negatives with a DR of 0.7 and 0.4 like this and they came out very good.
If your printing frame has no split back then POP will be a little bit of a hassle, another reason I did not like ziatype. I use a vacumm frame and it was difficult for me to judge the exposure and keep the print in register with the negative.
If you order the kit from B&S ask Melody to send you potassium oxalate developer instead of the ammonium citrate, I think you will be much more pleased with the results. PO gives very nice warm and rich tones that I found were more pleasing than the neutral tones from ammonium citrate. Again you might think differentely so remember this is free advice.
I am sure Carl and Clay will be better to respond to this question. If you decide to stick with this, then buying and mixing your own will be better and little bit less expensive (not much though).
Books, there is already a thread on that but here goes again, "platinum & palladium printing" by Dick Arentz, "the new platinum print" by Carl Weese and Dick Sullivan, "comming into focus" edited by John Barnier. I found these 3 were all I needed to get good info.
We are lucky we have Carl and Clay visitng this forum as between the both of them we can probably get any answers we might have.
Good luck and let us know how you like it.