The Super Smash Bros. for Wii U and 3DS Collector’s Edition: Prima Official Game Guide should come with other bonuses too since the amount of pages (336) is a lot more than the Super Smash Bros. for Wii U and 3DS: Prima Official Game Guide (288 pages).
The two books are launching on the 21st of November, the release day for the Wii U version. The 3DS game is already available as it came out earlier this October. If you have not yet done so already, the Wii U release is available for preorder with this link. The two versions have an identical cast of playable characters. If you buy both, you can also get Mewtwo as free DLC when the Pokemon is going to be made available as a fighter next year.