Which HID kits are you using? Most of the chinese one's are crap. A few good manufactures make a decent product. Digital systems are the way to go, but they are expensive. They produce a more accurate color and will be the same brightness from left to right (which is a problem with analogs).
The LC I believe uses a 9006 for the lows, 9005 for the highs, and a 9006 for the fogs. If you were to get these all converted to digital HIDs, you would be looking at 3 * $440 = $1320. That's damn expensive just for headlights.
Here's a good sight to look at. I've heard positive reviews from people.
Xetronic Digital Lighting System - 9006 Type (pair) - DBX9006
Remember you will also need a device to disable the on-board warning because it will show that your headlights are burned out, or just deal with the warning being on all the time (unless Toyota can disable this, I'm not sure.)
Also, remember that HID reflector conversion kits are not DOT legal and therefor are sold as "off-highway only". In the US, you will get a ticket if you pull up behind a cop with your headlights on. At night, obviously you have no choice.
HID reflector conversions are rude to other drivers. Being that your headlights are at the height of a sedans rear-view mirror, you will blind them with a powerful kit.
HID's were DESIGNED as projector elements, NOT reflector. Putting an HID bulb in a reflector housing just throws light everywhere.
The main reason why people use HID conversions is for show. It looks sick to have UV purple headlights with a deep yellow fog lamp setup.
I would just stay away from them personally. No reason to risk a ticket or spend the money.
To each his/her own though...