hi david

200 dpi is still pretty big .. a computer screen is only 72dpi resolution so it is pretty much overkill
AND if you upload large images, it will be a pain because you and everyone viewing
will have to scroll all over the place and never really see the image as a whole, but ... in pieces kind of like an abstraction ..

6" is about 432 pixies
5" is about 360 ...
8" is about 576 ...

have fun !
john