F-111's, Korn. F-117's are stealth fighters which only the US has
Anyway, yes, we do need to replace our F-111's. But there has been a lot of controversy over whether we need to replace them with an experimental plane, which has been subject to enormous cost increases (currently standing at over $65 million a plane, up from the original estimate of ~28), rather than something tried and tested. Especially when, I again reiterate, we are leaving the age when conventional airpower is going to do us any good.
As if our tiny defence force is going to be of any use if we got invaded anyway. Our defence policy is underpinned by the US defence force, not our own. All we need is an army that can go and provide assistance to the US in its wars so that we get assistance when we need it in return. Our fighters don't really do this (when is the last time you heard of a fighter or bomber actually being used? Our army, navy and aerial transports are all used, but not really aerial strike forces), so I don't see why we spend so much on upgrading them.