there used to be a full sized wireless keyboard?

Solution 1:

Yes, you can even still purchase it from vendors listed on this Google Shopping page. Unfortunately, that option will run you $120 plus whatever shipping they charge.

An alternative is purchasing it used off eBay, but I only found one listing for the full sized wireless Apple keyboard.

Solution 2:

Yup, you're right, but it is not in the style of the present day designs (flat aluminium enclosure, laptop style keys). It was of the older, chunkier keys present on older Apple desktop keyboards. It was discontinued in about 2007 when Apple redesigned it and released the present day design.

Details of older design