I'd go for the lower wattage bulbs, the brighter ones would be serious overkill. I have always found the standard lights to be pretty good once set up properly. I've had 3 Fazers and all needed the headlamps adjusted, i think they are set up at the shop without a rider but as soon as anyone sits on the bike the headlight aim is way too high especially with the soft rear spring.
Spend a bit of time setting up the aim left and right as well as up and down and you might find they are bright enough.
Jim.
you can find on youtube how to adjust your lights worked for me
I had the 35W kit and it was fantastic
Nothing is foolproof to a sufficiently talented fool.
I have now ordered a 35w HID kit, I want to have good lights as mine are not that good and they are adjusted ok