Just curious why you cannot pep? Is it just inexperience, or the tedious nature of it? I've never built anything in my life and then i tried pepping. Tedious yes but difficult? surely not.
What type of build are you doing if not a pep build? If your looking for a purchase look in the Junkyard there are a ton of helmets for sale.
But I would recommend giving pepping a shot, it's cheap easy and gives you a sense of accomplishment as you progress.
Hope this helps somewhat.
cheers!