new iPad + Nexus 4, good mix or not?

I've just bought a new iPad 16GB WiFi. I'm gonna use it mostly at school for making notes and internet. The device that I use more often is a mobile phone. That's way I'm wondering if a Nexus4 16GB and this iPad is a good combo. Wouldn't it be better to buy an iPhone 4S? Does anybody know, if Google i gonna make a re-stock of Nexus phones before 10.12?

Oh, i gotta another question. If I'll buy Nexus 4 in USA will it work in Poland? I read something about CDMA network used in US and which is not avalaible in Europe.

Thanks for help, and sorry for all mistakes if there're any :P