I've set up four 74141s and two shift registers (595s), but am running two nixies so far, and a bulb.
I'm using a spare PC PSU for power, the arduino is the one I fried so it needs to be powered from USB. I'll be adding a USB plug to the PSU as soon as I've been to maplin to buy a male type B plug.
Here's some pics:
Click for Big.
The rig (using a bit of Meccano to make a gantry to hold the nixies):
At the top is the 12v - 180v PSU.
Coming in on the right is a 5v line and a 12v line from the PSU.
The breadboard is 74141, 74141 and 595 (in use) and the same again waiting to be hooked up and an IN-35 bulb.
The arduino is sat on a bit of polystyrene and attached to the gantry.
The nixies are in sockets suspended from the gantry.