Any 4x4 Rodeo from 93-2002 will fit it, same part exactly!! You don't get the idler arm, just the relay box and it takes about 20mins to fit in place.
They are $330 new from Holden and that's at wholesale!!!!
There is a non genuine ones.
Suspension Autoparts in Wellington have new ones in stock for about $95 ring 04 5663277
$255.99 - retail price from Repco
In Chch try;
Falsgrave Auto Spares
70 Falsgrave St Waltham Christchurch
0-3-366 2374
Giltrap Commercial/Spares/Truck 4x4 Sales
608 Halswell Rd Islington Christchurch
0-3-349 5962
If you want overhaul one it's quite a straight forward repair but you need access to a good press and a lathe. You can add a grease nipple to the idler body to make the repair last.