dont forget about pressure here guys: certain fans are built for high pressure applications like blowing air thru smaller holes (variance on the fan blade shape)
anyways, ive noticed they carry them at my local radioshack
you might be able just to walk down there and pick one up.

Sony PCV-RX755 (old but still runs great!)
MOBO: ASUS OEM board
CPU: 2 GHz Socket 478 Pentium 4 Northwood
RAM: 2 GB Kingston ValueRAM
GFX: EVGA Geforce 6200 AGP
HDD: Samsung Spinpoint 100 GB ATA-100