Of course you should buy a Rover.
Rover, the British Company, has now been gone for 11 years.
You would think due to the company now under Administration parts would be hard to find or expensive, NO.
There are many, many MG Rover based garages across the country and many MG Rover Forums where you can find help, advice and cheap (ish) parts!
Rust? Well that depends on what Rover you were thinking of buying! The Rover 25 has a weak-spot for rust near its right headlight; it isn't usually that much. The Rover 45 has a similar problem - but nothing to worry about! The Rover 75 is a very well built car and we had one from 2003 - 2016, unfortunately we sold it to a garage due to us wanting a new car. (Great Car and Pretty Cheap British Luxury!)
The only thing that wasn't that great on the 2.0 litre v6 is that is drains fuel.
Hope this was helpful,
Kieran