eh.....i dont know about the info target, but if you want to make it look like the light is shining, then you have to create a brush that is the 'beam of light'. so make it come out of the light at the top, and expand it a the bottom. now you need to give it a texture, which should be 'FADE2' from the halflife wadfile. make the texture fit each side so the bright end is at the top comming from the light, and the dark end at the bottom. now make this brush a func_illusionary, and set the render mode: additive, and set the fx amount at somewhere between 200 and 255. now if you want some glare when you look at the light, put in a env_sprite right where the light emits, and in the 'sprite name' field, search for 'blueflare1' which is in your 'half-life/valve/sprites' folder (note: you might have to copy and paste it into your esf/sprites directory if it doesnt show up when you compile). also, you might want to take away a few of the stadium lights if your going to do this, because if you do this for everyone of them, then it will look really weird
EDIT: light_spots dont lag...breakables do
