Yeah, first, how much current do they draw and how much current is available from your stator?
would you check the output by hooking up a meter to the battery rev to 3,000 rpm, should be 14 volts , then hookup a headlight from a car 55 or 65 watt and see if the voltage drops at the battery, and check it at 1,500 rpm , to see if it would suck the battery dry at idle, if you can put two lights on you should be OK to hook up any spot lights , some spot lights LED take only 15 or 20 watts,