well youve 100w o play with, so, tot up what drainage on the batery you will have. its just simple match, forget about volts and amps. assuming you have 12v neg earth, add up everything, now its not necessarily all about keeping under 100w, cos stuff like indicators and brake lights might take you over your alloted amount, but you will not have them on all the time, so, headlight at, lets say, 55w, means you have just 45w to play with, heated grips may take you over that leaving you with a flat battery eventually as you use more power than you can put back. stop and tail lights use 21w and 5w, indicator bulbs use 21 watt each, just do the maths. 100w isnt a lot, i suspect you are going to have to compromise. you might save valuable watts by fitting led lamps to your lights, perhaps a super bright led sidelight so you can run without the headlight until its propper dark.
