I just tinted my windshield with a 3M Crystaline 70 and on the two front windows with a 3M Crystaline 40. The Crystaline 40 on the side windows would probably not be dark enough for you but you should check into the 3M Crystaline tint for your windshield. It's excellent at blocking heat and UV rays. You can get the Crystaline tint in an almost clear shade, a 90, or you can go as dark as a 40. As far as safety is concerned, adding tint to the windshield actually makes your vehicle safer. (assuming your not going too dark as it is illegal) If anything hits your windshield the tint adds an extra safety layer and the glass shards would also be contained and not come at your face.
Check out the 3M link... http://solutions.3m.com/wps/portal/3M/en_US/Window_Film/Solutions/Markets-Products/Automotive/Crystalline_Automotive_Films/
Check out the 3M link... http://solutions.3m.com/wps/portal/3M/en_US/Window_Film/Solutions/Markets-Products/Automotive/Crystalline_Automotive_Films/