As said, an all alloy Savage would be useless at anything other than looking 'pretty' sat on a shelf.
Diff upgrades should be your first point of call.
Thicker TVPs from the likes of Innovative-RC or Alza Racing are a worthwhile upgrade, not only do they add strength, but they improve the way I'd drives because they lower the centre of gravity. Another weakness that is worth addressing is the bulkhead braces, they are prone to snapping after heavy one-sided impacts, and often take the bulkheads with them. Alza Racing bulkhead braces completely solve this problem.
Alloy does have it's place, but only if you use decent manufacturers and use it where it actually has real benefits (like the above mentioned bulkhead braces) and not just to look shiny.
Savage X A-arms are more than up to the job, my truck is heavy and I'm yet to break one. If you have the old style arms, an upgrade to the Savage X ones are very worthwhile.
With a mixture of Alza and IRC upgrades my Savage is pretty nuke proof now, but there's no need to go that far, just upgrade to Savage X spec whenever you break things and enjoy it!