I got the Sylvania lights before I got my HIDs. If I remember correctly they cost about $50 and I did notice a difference but compared to getting real HIDs there is absolutely no comparison. I would not have wasted the $50 on the Sylvania's if I did it again. You can get a good set of HIDs for around $150 and be done with it and will have much brighter headlights. I would look at RetroSolutions:
55W DIGITAL HID KITS - Retro-Solutions Store
As for installation, new bulbs are super easy, simply turn the bulb on the back of the headlight housing and it will pop out, insert a new bulb and turn it back into the housing.
HIDs are pretty easy too. All plug and play.