Floating World is amazing, and that is a really good price for it. Highly recommended.
Tomato also did a Gas Book, which you can see here:
http://www.amazon.com/gp/product/486...SIN=4860831853
It's out of print, but you may be able to find it cheaper from other sources.
There's also a companion book to Floating World, Idea Magazine 337.
http://www.idea-mag.com/en/publication/337.php
Idea Mag 286 is also an Underworld/Tomato issue. These aren't really magazines so much as books. They're like 200 pages each.
http://www.idea-mag.com/en/publication/286.php