What you can do is go to a vendor site like digikey.com, mouser.com, etc., and search LEDs. For example, if you go to mouser, go to Optoelectronics -> Led Indication -> Standard LEDs (through hole), and select the color Red. That narrows it down to 1339 choices, with luminous intensities from 0.1 mcd to 65000 mcd. Intensity is a function of how tightly the light is focused, of course. An LED with a narrow viewing angle will have high intensity compared to the same thing with a wide viewing angle. It could be the same physical LED die inside a package with a different lens, that's all.