Yes, Humvee is right. The actual tool sets are very rare and expensive, and often aren't screen accurate even when you find them.
Karol and I make resin replicas of the hydrant spanner. I am sold out at the moment and don't have plans to make more. But Karol currently has the mold and might be able to make you one (but don't bother contacting him until after Oct 1st, as we are both very busy with Wasteland Weekend 2011).
I have a local leather shop that has made me very good replicas of the spanner pouch in the past. I could probably get them to make you one for about $40 (but they don't do mail order or anything so I'd have to take care of it for you). I'd recommend you get the spanner in hand first before you order a pouch from me.
The axe is a bit easier. Fairly accurate axes with leather pouches can often be found on the UK version of eBay. Just search for fireman's axe. The vintage British versions are nearly identical the Aussie ones.
That's it. You only need the spanner and axe with their pouches. The belt (and anything else) that comes with a complete set of NSW tools is not used for the Mad Max costume. He uses a different belt (a Sam Browne belt).