If you are building something custom anyways, or want an easier to replace fuse maxi fuses are a nice option that are readily available.
mostly oem plus is my style, and i've been driving diesel vws for 10 years now and this is the first glow plug fuse i have blown, so i don't plan on changing anything about it.
I just used a maxi fuse block. Works great and fuses are readily available for a couple bucks a piece. Can't post a link, but you can get them at Pep Boys, AutoZone, etc...
i has able to get them from napa for 30 cents a piece, but i had to buy 5, will post part numbers then
Vwpartsplace.net has em too
Make that partsplaceinc.net
This glow plug fuse is one thing I've always found in stock and the VW dealership.
Now they have many of the common things I buy there in stock, like seat sliders.
I guess the computer keeps track of what I buy and tries to keep it on hand.
Napa numbers are atm-n1771253 for 80 amps and they are atm-171251 for the 50 amps