advmonster.com is another great source for lower cost LED lighting.
One thought to add:
I was told that creating a light triangle helps others calculate your approach speed better. The triangle getting larger registers with our brain very effectively. One common way to die on a moto is having a car/truck turn in front of you and later say, "I didn't see him" or "I thought he was farther away". Supposedly, in Europe, you cannot put aux. lights in a row, ie, one on either side of the headlight, due to this perception issue.
Also, the bigger the triangle, the better this works.
My PIAAs on my brake calipers have kept everyone away from me (I run them day and night) and even make some drivers pull to the right to let me pass. (How polite!)