For starters, I'd donate most of my money. But as for the rest of it, welll.....
I'd buy my cat his own little cat tree jungle, where he could climb to his heart's content. Sorta like this.
http://extras-ehow-com.blog.ehow.com/files/2014/01/cat-tree-1.jpg
https://s-media-cache-ak0.pinimg.com/736x/ca/3a/6d/ca3a6d9990e355df6a9d14c7497c4e8b.jpg
Because I love my cat that much! Perhaps Squilliam would do the same for his pet?
I myself, well... I'd want something like this...
http://www.oasisofeden.com/images/themed/Jungle1.jpg
Yes, I'd want a genuine jungle room like this. Or something similar. Also, to fit the theme of the room, a giant stuff animal.
He'd be the first thing you'd see upon walking into my room.