There are a number of things one needs to keep in mind while looking at an outdoor kitchen. Getting the right advice up front is probably the single most important thing we can suggest.
Selection of materials is probably the second most important thing to consider. Even under an alfresco roof it is a very different environment compared to inside your house. The materials needed to withstand long term exposure outside will cost more, but when cheaper alternatives are used, you will be disappointed in the not too distant future.