I don't have any personal experience with it (not many will have experience with a 5-foot barbell), but if looking at Amazon, this is the only one I can find that is rated for more than 300lbs:
http://www.amazon.com/Body-Solid-Black-Olympic-Weight-Lifting/dp/B00HAUSNAM
You may think 300lbs is a lot, but personally I try to stay under 50% of a barbell's max rating. Just like you wouldn't drive a car at maximum speed all the time...
Also, they're all less than the standard 45lbs, which is not a big deal, just make sure to factor that when counting weight.
If you want higher quality, Rogue makes a Junior bar that is roughly 5.5ft long, but has the regular distance between the loading sleeves, which mean you won't sacrifice stance and it will work with any regular power cage of olympic bench. It will also spin better (less of an issue for bench and squats) and last longer. It's significantly more expensive though.
Are these like all the same bars?
http://www.amazon.com/Body-Solid-Black-Olympic-Weight-Lifting/dp/B00HAUSNAM
http://www.amazon.com/Body-Solid-Oly-Power-Black/dp/B005PGBF8U/
http://www.amazon.com/Body-Solid-Oly-Power-Black/dp/B003TPRM2C/
http://www.amazon.com/USA-Sports-Troy-Barbell-Olympic/dp/B002Z5ZKMG/