Basically i want to run a home hifi system in the van. Iv'e looked at the Wattage and realised that the amp is 300W and the CD multichanger is 10W so altogether this will be 310W. Iv'e recently purchased a 500W power inverter for my car battery and have yet to recieve it. I'm hoping this will work but if someone has done the same or tried and failed, could they let me know please as this would be a big help. If you need any more info to determine the outcome, let me know also. One more thing. If i was to wire this up and it worked, how long would it run for as the inverter states:

Continues AC output: 400W
30-minute AC output: 500W
One AC power output
Peak power: 1000w

Many Many thanks!!! Please help