Well, if you have your receipt, march that stuff right back to the guy who sold it to you. If he doesn't like it, he shouldn't have sold it to you.
I know what you mean about conflicting information, a person could go crazy trying to follow all the different do's and don'ts out there. What I WILL say, is that since I've found this place, I stopped looking all over everywhere for info, I just come here. I will also say not only are my snakes happier with the info here, I'm happier too.
If you need to make due with the Faunarium for now, a damp towel will help, but be aware you'll need to change it frequently to prevent any chance of mildew or mold.
Derek had the right idea when he told you to hit Ebay, he lives in the UK as well and he'd know what the easiest and cheapest route to go is.
I'm guessing the reptile store guy told you about the moss thing because that is what people use to create what is known as a "humid hide". These are mainly used by people in extremely low humidity areas because it's just about the only way to help their snakes shed. In your case, he probably told you to use one because he knew that enclosure would never hold proper humidity.
Take your time and explore the site here. There are some of the most wonderful people and the best information anywhere to be found here.
Best wishes to you and your future baby!
Gale