Ive done a full HID kit on mine, so I can be of help. I was Lumens products that I got from my local shop.
Lumens High Performance Lighting - Xenon HID Conversion Kits and OE Replacement, LED Lighting
The install is easy enough. Im assuming you have a GX or GS/Sport or Touring? Also, if you are in Canada, you will need a DRL (Daytime running light) relay harness.
First picture are the bulbs and ballasts, 2 of each. Second picture is DRL Harness. Third is stock / HID Comparison (This picture was taken with a 8k purple bulb, using 6k instead now). Fourth and fifth is where I mounted the ballasts (Just under the plastic flap on either side of the engine bay. Sixth is where the harness (Optional, from my knowledge, Americans and elsewhere don't run DRL's) is hooked up to battery. Seventh is the current 6k HID's I run.
If you require step by step instructions for install, I can recall what I did for you best as I can, otherwise you can follow an install guide that Im sure is on the internet somewhere. As for how much better they are, they are differently more clear, brighter, and looks a lot better. Worth the 150ish I payed for the bulbs and ballasts, and 30 for the harness.
Edit - Turns out I cant post more than 5 photos, so Ill post the next few pictures after you reply.