if you could sneak a pic of his setup that might help people with suggesting add-ons (i.e. a "thumper" or something that may help with double distilling).
Or if you are not looking for something to add to his set up, you could always go the route of personalized bottles/labels.
or my favorite...if he is making whiskey, you could get him a charred white oak barrel from online, they come in different sizes, but a 3 litre size is just right for a newb because they aren't putting too much into it in case it comes out wrong. There are a few sites that sell them online for around $50-$75, you can get them personalized, and he could age his whiskey in the barrel anywhere from 3 months to a year to get a flavor he liked.
I had some whiskey "made"
and put it in a barrel and love it...homemade bourbon!