As far as buying on Ebay, there is no way I would. First off you have to find out if it has a US warrantee. Second there is the issue of trust and all that good stuff. I would look at photographic mags and get from there. They have good deals and the couple bucks you spend will be worth the piece of mind. Still make sure it has a US warantee.
As far as Nikon not being a quality camera that is just not true. Is it still the camera of most profesionals. Yes. Has Canon closed that Gap, they sure have. You will be happy with either cameras. If you want to go black and white you may want to look at medium format stuff as well. Then Ebay can be a good source.