PWM pins work the same way across all Arduino boards, so you don't need to go out of your way to buy a Mega if you already have a board supporting PWM. On the Uno, Nano, and Mini, the PWM pins are ...

Options to power the Arduino Nano include USB, VIN, and 5 volt pin, meaning you have power options for almost any situation. ... The Nano even has more analog pins than the Uno (eight vs. six), ...