I get Valvoline Maxlife Full-synthetic ATF @ Walmart for $18 for a 1-gallon jug. I use it in two, R51 Pathfinders, which have over 200,000 combined miles on it and it still shifts like new. I also use it in the transfer cases and power steering...and in the transmission and power steering in my 03 Frontier SVE.
Nissan Blue coolant, the same as Pentosin Pentafrost A3, is an extended life coolant with a service life of 135,000 miles/10-years. It can be mixed with other anti-freezes, such as Nissan Green coolant, but it will shorten the service life. Your best bet is to stick with Nissan Blue or Pentosin Pentafrost A3, which is sold on Ebay, Amazon, Rockauto.com and even in some of the big-name parts stores. The blue only comes in premix, so no adding of water is necessary. When servicing, I usually use 2 gallons.