I cannot find the Deck Editor. Where is it?

The Deck Editor is shipped together with Wiz Solitaire. When you download and mount the dmg archive, you’ll find these files:

WizSolitaire-*.dmg contents

Typically, you should drag’n’drop the whole WizSolitaire folder into your Applications directory. In this way you’ll also install the Space deck, which you can use as an alternative to the Standard one (other decks are available for download).

Is it possible to play Spider with more than one suit?

Yes: you can use the New Game with Options… item under the Game menu to choose how many decks you wish to play with.

You don’t need to do it every time you start a new game, since it will remember the last used setting.

The same menu item can be used to set the options for other games as well (for instance, in Klondike you can use it to change the number of cards dealt when clicking on the deck or to allow partial column moves).