If my information is correct the Low beam is a H3 bulb on your 6th Gen projector lights. There are HIDs made for the H3 bulb fitting, so yes, you could install a HID kit into your projector housing to make it brighter.

K2 makes HIDs for H1, H3, H4, H7, 9004, 9005, 9006 and 9007. You can also check Philips and check what bulbs types they manufacture for. A HID kit will run you anywhere from $300-$600.

The "round thingie" you speak of is the projector. It is not as simple as just plugging in the bulb, you actually have to do some wire work. However it isnt something that is too difficult.

Sylvania Cool Blue bulbs are not brighter than stock. They only seem brighter because they reflect off of certain surfaces such as road letters and certain street signs. In reality, since the acutal bulb is covered in a tint, it hurts the light output of the real bulb.