Colorbond will look handsome on that home. If it were possible to repair the roof and retain the tiles I'd do it. But if budget does not allow then sure a tin roof will be fine also. Australia has a long and proud historical use of tin. I live in a heritage town, every house in it from 1880's right down to 1960's has a tin roof, including many homes of that era. If that house were weatherboard built in the exact same year, it would have a tin roof anyway. I'm a history fan, I'm a preservation freak, but sometimes practicality needs to take centre stage and that is exactly what the people who built the house would have chosen had their budget not allowed the tile.

For my money, given the lovely colouring of your brick I would go with a Jasper roof, that nice bronze with pick up the detail of your brick and look good and also work with the existing trim. Another thing you can do to avoid the cheap roof look is choose a different profile to the tin. This roof is the same pitch as yours on a similarly proportioned building. The profile however is what makes it look more heritage than a standard corrugation. Not sure if BHP do this profile but I'm pretty sure that Lysaght do.

The one thing I would be careful not to do however, is change the pitch of the roof if the trusses also need to be replaced. It's pitch is an essential character of that home and are necessary for right proportion.