Those clears are from Origin, G Corporation...etc, but as far as I know, all of them are same ones made in Taiwan. I have a set on my car and they look pretty good. Quality is not as good as OEM though. If you have a car with dark color, smoked ones will look nice too.
http://www.g-corporation.co.jp...3.jpg
Clearcorners used to have their own version of tail lights(half white rather than clear), but it's not available anymore. I emailed them a month ago and they said S13 coupe tail lights are under development and they will use LED. He also mentioned that the price will be very high.
Your best bet will be buy a pair from eBay.
http://motors.search.ebay.com/...prchi=
BTW, red portion is not red enough for these eBay clear tails, so actual light looks like PINK. I put red colored bulbs, and they made a huge difference. If you own these clear tails, you might want to try that. If you put new Eclipse bulb($30+ ea) for blinker, you can make clear part really clear(no amber inside). It's called stealth bulb or something, so it's amber only when it's on.
I tried Candy Apple spray on another car for all red tails, and it looked good at first, but eventually paint faded away and glossy look was gone. You should clear coat it if you want it to last longer.