To be safe, I would search for a secondhand 45W white brick on eBay or elsewhere. As far as I know, Apple only sells the 65W ones as replacement/extra parts.
Cheers! :-)
- JediJoker

- "ProBook:" 15.4" MacBook Pro Core 2 Duo 2.33 GHz
- Mac Classic II
- Old PowerBook

Moved On:
- "The Book of Power:" 12.1" PowerBook G4 Aluminum 1.33 GHz
- Purple iMac