I don't know what sort of cars you are particularly looking for (strictly international or some domestic only) but as a comparison with the Monaro could we possibly have the FPV F6 Typhoon?
Edit: (see below)
Background:
FPV is a 51/49% Prodrive/Ford group that produce performance versions of Ford Australias performance line-up.
Ford Australia introduced the XR6Turbo late in 2002. This was powered by a turbocharged 4 litre straight 6.
A couple of years later FPV finally released their souped up version of the XR6Turbo. And indeed it was this the F6 Typhoon. The car featured a bigger turbocharger and re-mapped ECU, along with that massive intercooler that you can see in the front grille. Power is just 270KW however Torque is a massive 550Nm. At release it was the torquiest Australian produced car of them all. I think that it still is, however I am not 100% sure.
Since its release it has received critical acclaim (aside from an early clutch issue that halted production for a couple of months).
So essentially the car is not unlike the Monaro except it has a big turbocharged 6 rather than a big V8. They are both a bit on the heavy side, they are both pretty fast (although this one is actually speed limited to 230kph or 140 odd mph) and they both drink a lot of fuel.
In Australian spec the Fords tend to be set up more for a sideways sliding experience than the Holdens, how it compares to the Vauxhall set-up however I have no idea.