Love2Fish
Aquarium Advice Regular
If it's anything like mine was when I got it it will end up costing you a lot more for all of the little things added to it than you expected. I would look into ebay, maybe you could find a cheap hood from there. I have a big titanic looking thing in the middle that they can hide in, it seems to take up a lot of room but they love it, so maybe you should kinda get an idea how much space the castle thing would take up after all because a lot of fish rely on good hiding spots