Will Nano work for what I'm doing?

Hello. First post, but I've been lurking for quite a while. Trying to learn as much as possible, have learned alot so far, you guys rock! But I still have a long way to go.

I've been starting a new project that ive got mostly figured out on a mega board (since that's all I had) and I need to make this whole arrangement fit into a fairly small case, and want to know if a nano board will work for what I want.

Basically, I have 3 lights I'll be controlling, now they are LED's but I will need to figure out a brighter light later. I also have a speaker, and IR sensor and remote. And lastly I will need to play beeps from the speaker, as well as a sound file. Ive got most of this figured out on a mega board, but wanted to know if a nano board can handle it.

And basically what I'm building is a cosplay prop. A shock collar (TAME Collar) from the movie zootopia. Basically i want to use the remote to use 3 buttons. First button turns on a green light and plays a beep, second button turns on a yellow light and plays a deeper beep, the third button turns on a red light, a really deep beep, And then plays a sound that sounds like an electric shock . I've got alot of it figured out and coded on the mega board, but its just far to big. I'm going to be making a case out of resin and it has to be small enough to fit on a collar around my neck. I have a lithium usb battery pack ill keep in my pocket and run a cord to power it.

The main concern I have is weather the nano can handle this, or if there's a different board i should be using. Sorry if this seems really newbish, I just can't find any sources describing to to determine which board is best for certain functions. Thanks!

How many digital pins are used? Nano has 12 digital pins (2-13) plus 6 analog pins that can be used for digital. How many are PWM pins? Nano has 6 PWM pins (among the 12 digital pins). How much SRAM does the sketch use? Nano has 2K bytes. How much flash memory does your sketch use? Nano has 32K bytes (minus, at most, 2k bytes for bootloader).