Worth to get the vita now?

Go for vita 1000 or vita 2000 slim?

What is the difference between vita 2000 slim previous generation and the latest generation with blue/orange colour?

The save files for games are saved into the removable memory card, right? I am trying to switch account to my second removable memory card (8GB) because I want to play games tied to another R1 account, but am afraid that my PG4 save file from my first account will be deleted from my first removable memory card (32GB). Can someone confirm this?