Adding one off products

Let me see if i can address the various items.

Firstly for Sku quantities, you can indeed create a 1 off sku and set its quantity to 1, and there's a radio or drop down that asks "do you want to track inventory?" and "If none left, disallow purchasing" (something like that). So you can have it either not show, or the default transformation of an item will have the "Buy" button disabled automatically if it's set up this way.

Not sure also why you would create a new category...may be good to have one off skus in a "one off" sku category for easy display (select all 'one off' skus), but otherwise i also fail to see what this would accomplish.

Thanks Trevor! I was getting myself wrapped around an axle trying to make a new category work.

One last question. I create the stand alone sku...do I then associate that some how with a product or a page or will it display just by filling out the information in the stand alone sku page?

A Sku is still (more or less) a "Tree Object" so you do need to repeat it on a page (this is where having them in a specific category may help, you can do in the where condition "DocumentID in (Select DocumentID from CMS_DocumentCategory where CategoryID = (Select CategoryID from CMS_Category where CategoryName = 'OneOffSkus'))"

I would reference Kentico's base Corporate site to see how the transformation renders the products on the page with the Add to Cart logic. As long as the Sku is set up right with the inventory and "Don't allow if none in stock" things set, i believe Kentico should take care of that portion of things during the checkout.