For the reverse lights I went with 15W HID kit. Not sure about the first gen car but on my '09 lighting pattern is like having small head lights or fog lights on the back of the car. It is a PnP kit HID lamp has a silicon rubber base that snaps in place of the OE lamp holder Power to the ballast is supplied by a plug that is inserted in the the lamp socket. Had them for about 4 years now with no issues. I have tried 35W ballasts generate a lot more heat but not enough additional light output to justify using them.
For the floor lighting I used a couple of these kit.http://www.alpena.ca/Product.aspx?id=1088&webcat=14. I used the dome light to trigger a relay to power all the LEDs on an isolated power circuit.