Hybrid Customs, your question of Silverstar's or Xenon HID's is like asking if someone should buy a Civic or a BMW M3. The answer depends on how much money you are willing to spend.
The cheapest and quickest way to get improved lighting is to buy replacement bulbs, such as Silverstars or PIAA's. I personally recommend PIAA's, but Silverstars are also a good bulb at the price. PIAA's cost about $50-70 per set. I'm not exactly sure how much Silverstars cost, but I'm pretty sure they are about half the price of PIAA's. Keep in mind, the bluer your light is, the worse your visibility will be in rainy weather. Blue/purple light doesn't illuminate well in the rain.
Xenon HID's will greatly improve your visibility at night and in all weather conditions. Getting a blue or purplish HID will still give you great lighting in rainy weather (I have 12K purple HID's on my Civic). Xenon HID's generally have about 2-3 times the lumen output of a halogen bulb. The thing to keep in mind is to stay away from eBay cheap generic kits. Cheap kits often don't last long, and aren't much brighter than halogens. XenonDepot who sponsors this thread sells great quality kits. My personal favorite is the McCulloch Kit which can be ordered from
www.xenonpros.com (if you order from them, call in the order, and tell them you want the eBay price which is about $100 less than the website) A Xenon HID kit will cost about $275-400 for good quality. The install of a Xenon HID kit is not super difficult, but if you're not comfortable doing it yourself, you can get a local tuner or car stereo shop to install them for about $50-80.