Creating a volunteer form

Hey guys, i have an event, where i want to have volunteers sign up and pick a position to volunteer for.

What's the best template or option for me to include, that will show a list of positions to take or select, that will then "gray out" or reduce the number of positions available?

For example: if i hae a selection, that has 5 spots available, can i have someone register for it, and when they do, it reduces the availability shown to 4 ... and so on?

That can be achieved with Appointment slot widget. 

Similar widgets:

Ticket Purchases

Inventory

Quantity Gift Registry

Inside of this guide, you can find how to add a widget to your form:

How to Add a Widget to Your Form