I might suggest this place:
http://www.ddmtuning.com/
I bought a set from there (55watt, 5000K) when I had my 97.5 Regal GS some years ago. They fit in that, my 2006 Grand Prix GXP, and now my 01 i30 as well. They are simply plug and play w/o having to change anything on the car...the hardest part was determining the best spot to mount the ballasts...which on the set I have are pretty slim (1/4" or so). That said, it appears they have changed a bit since I bought mine...the ballasts appear smaller in shape, but seem a bit thicker now too, though it is hard to tell from the pics...if they are thicker, it's not by much.
One of the best upgrades you can give your car...the change is quite dramatic.