I would pass on it for now. The batteries may not hold as long of charge anymore as when new. The lens is OK but heavy, you can get a better lens form Sigma For the money you would spend for that lens. The cases can be had for less than he wants on eBay. Also the camera is to old, you can go to Costco or Sam's and buy an new camera that is ten times better.
Now I still shoot with my Canon 20D and feel it is fine for what I do. I would like to upgrade to get a camera with 1080P movie capability but don't want to spend the money now. You need to write down what you want the camera to do and then see what system fits your budget. Then I would buy the unit that is one step up from there.
And as for what brand to buy...........look for the best deal in either and go from there. they are both great brands and do basicly the same thing. The picture quality is 80%lens and 20% camera and so is the cost nearly in the consumer level to prosumer.