I agree with most of those above. I went the total LED conversion as I went to Magic Blinkers for my front turnsignals to be on FULL TIME. I added up all the wattage of the standard incandescent bulbs and the special resistors needed to load the turnsignal relay and went the LED route. But the pay back time is very very long. The two bulbs for the rear cost about $17 each. The "Superbright" 1157 LED's I got are a bit brighter than the P21/5, about the same as a P28/8 (91 Kaw Ninja 500). A P21/5 is 5 watts on running and 21 watts braking. The 1157 LED is like 0.2 watts running and 1 watt braking.
That $34 cost will take years to recoup in gas mileage. If you want a slightly brighter bulb see if a P28/8 will fit. It will run a bit hotter than a P21/5 but it works in the smaller Ninja 500's housing. This is assuming you are talking about a P21/5 bulb.
In my case, phase 1 was to install a set of Magic Blinkers, and two 20 watt resistors for the turnsignal relay so it did not think I had burnt out bulbs up front. These resistors added to the NOW ON full time P21's up front, it was a lot of wattage. By going to LED's in the turnsignals front and the Brake/running lights rear, I saved the wattage added by the load resistors. Phase 2 was to buy a LED turnsignal relay and cut the factory wiring and install it. I could then remove the load resistors. Oh, I was also running heated grips, a heated seat pad and a 50 watt fog lamp. Lots of wattage.