Part of the attraction of Arduinos is that you can do everything yourself. Please post your code if you want help with it. There are lots of willing helpers.
If you REALLY do not want to do this yourself, then you should be posting in Gigs and Collaborations, and you should bring your wallet.
Powering the LEDs may be a problem. Those RGB leds need a lot of current. In the video, you can see a large usb battery pack. You cannot substitute that for a couple of coin cells. How large is the dog? Where will the battery be kept?
Unless it is a small dog, I would recommend a Li-ion battery, 18650 size, with protection circuit built-in. This is can power the attiny and the LEDs for some hours, but it's small enough to be attached to the collar.
I’ll be using a already made led dog collar and taking the guts out. This convieniently gives me the slot where the battery went to be able to fit things. I will be using 32 diodes and have ( at least right now) a 1ah pack. I’ll be making, or repurposing a case to keep it all looking good. I have what I want as far as what the neo pixels will display. I’ve then thinking of adding a momentary button as my power instead. Short press on, short press off. But would also like it where a Long press would change to a different display pattern.