If you buy a genuine ATI card, the only difference is the clock speed. Also the 8500 LE from ATI doesn't have any sort of DVI connector. I have an 8500LE from ATI and the DVI is not present. You can pretty much overclock the 8500LE to 8500 speeds, without too much hassle, consult Rage3D.com forums for more information.
Cards from other companies like Hercules, Gigabyte, and Sapphire, have speeds which are usually lower than ATI's and may have different features. The same holds true for 8500LE/8500 OEM boards.