Get the Wii U now. Get the PS4 in a few months or whenever you have the money down the line.
You'll avoid:
● Launch Software Issues (Glitches, Freezing OS, slowdown, etc)
● Launch Hardware Issues (Overheating, RROD, etc)
● Launch Window Games Issues (Rushed, feature/content deprived, limited selection)
● "Features not ready at launch" (Kinect voice commands, PS4 bluetooth peripherals issues, etc)
You'll be able to:
● Read impressions from others on the hardware (does it work as advertised? Does it do what you're hoping it does?)
● Read neoGAF on the subject of the various launch exclusives (is Knack as middling as it seems? Is Killzone really a keeper? Is Ryse going to be the next God of War?)
● Stay out of the fanboy nonsense ("I'll be sitting over here and playing Super Fucking Awesome Mario thank you very much guys.")
● Support a system that is actually doing proactive things for gamers as well (no paywalls, great indie support, interesting a novel hardcore gaming features)
● PLAY FUCKING PIKMIN 3 AND SUPER MARIO AND WONDERFUL 101 (cause seriously guys LOL at Xbox One and PS4 launch lineup exclusives compared to those three alone)
You know the answer.