I say go aluminum, e.g. Allez or CAAD.
Crashes are fairly common in Cat5 amateur races. If you're on a budget, drop $1000 on an aluminum bike, and you'll be half as upset as if you crashed that $2000 Wilier that stretched your budget.
And, of course, the performance will be nearly identical.
If you make it to Cat4 or Cat3 without getting wiped out by your hospital bills, then you can drop some dinero on a nice bike.