Hello KnLMedlin and welcome to the family, we are so glad you decided to join us and we look forward to hearing more about you and your grey.
You want to put the cage where the family spends the most time when they are home and if the den is that room then fine, I have Josey's cage in the family room, that works for us.
Josey does accompany me in the kitchen sometimes when I cook, it is not the cooking so much as what utensils you use, for teflon and non-stick cookware pose a hazard to greys. If you rid your home of that material then the kitchen does not have to be off limits other than to use precautions when using the stove to they don't get burned by a hot pan or a hot eye on the cooktop.
Take a little time and read thru the many threads for lots of useful and helpful information and do not hesitate to ask questions you may have. We will do our best to get you some answers and help you in any way we can.
You didn't provide much information in your first post, but if you already have your grey and you have any pictures you would like to share with us we would love to see it.