Category RSS and Sign Up Form w/ Checkbox

My site is https://eugenepawn.com

Right now we’re using a plugin called Category Specific RSS to direct users to a specific category of product we sell (i.e. electronics, jewelry, etc.). From there they are able to signup to receive notifications about new products in a specific category.

Is there an easy way to do this where we can have this:

Enter Email Here
< input > [email protected] </ input >

Checkboxes for each category
_ Electronics
_ Jewelry
_ Guns
_ etc.

< SUBMIT BUTTON >

So, in the end it’s just a matter of a checkmark next to a category and a one-time click solution.

We also have a developer’s license of Gravity Forms if there’s a solution through that route and an Add-On for it.

Any help or suggestions would be greatly appreciated, thank you.