Hiding variants when stock reaches 0

Hi,

The wesbsite is www.allseasonsbbq.com and the template is Indigo.

My products have 4 variations (weights) and some sell out faster than others.

I have customers who are getting frustrated having to click through every variant in my drop down box, to find 3 sold out and the final option in stock.

I'm hoping to find a solution that makes these options in the drop down list either hidden or having a strikethrough effect, so that it is clear they are out of stock and my customer doesn't have to select it to find out that it's out of stock.

Does anyone know if this is possible?

Thanks in advance.

Mike