As the previous answer suggests, a CPA would be the best person to answer your tax questions.
The advantage to buying a property with cash is that you may be able to negotiate a better deal. Sometimes you can get a substantial discount with an all-cash offer. Other times, the discount may be modest. And sometimes you'll find the seller won't give you any discount.
One disadvantage is that you're tieing up a lot of cash into an illiquid asset. Especially if you're a widow "of a certain age," make very sure that you've got enough cash and other liquid assets before tieing up a chunk into an illiquid asset like real estate.
Hope that helps.