When you mean fixture, do you mean one that is ready with a plug to power up right away?
Do you have a 55w lamp? How much are you willing to spend?
Provided that it is 120v 60Hz, or has a 120v tap, I can wire it up myself. I`ve got a 55W lamp. Right now I could only pay (including shipping) around $80.00, wich I realize is not very much. But I do get another $5.00 every week, plus I randomly get money sometimes.