My friend had this happen to hi 155 V6, which is a very similar technical design. In his case the corrosion wasn't spotted until the subframe split and one side of the suspension nearly fell off!
His car is an L reg though so 8 years is a bit rough for you.
As Bodger says, its a 4-5 hour job but it actually doesn't take any specialist skill so it is doable yourself if you are handy (preferably with a mate) or by most any garage. It doesn`t have to be a specialist.
Its a good opportunity time to change front roll-bar, steering rack or clutch as they are all something that will be easy with the subframe off (you can`t do the former two without it off).. Also the front suspension has to be disconnected so it's a good time to replace any worn wishbones, shocks or springs. Why not, if it's coming apart anyway? You could even uprate it
Getting one from the scrapper is the best idea. They won`t cost a whole lot and are generally just fine - I think you have been unlucky. Cleaning up the second hand one and slathering the whole thing with waxoil or some other substance is definately a good idea though.
Oh yeah, and when it is all back together again get a 4-wheel alignment done or you will crab down the road and wear your tyres quickly.