I have an iAV 5 dock I can not get apart
iHome+Radio is available, but not in the US app store.
Power supply replacement
Any compatible barrel style 10V 1.4A power supply should work if you ever need to replace it. It's okay to go over on the amps since the dock will only pull what it needs, but do not exceed 10V or the dock will be damaged. The adapter is sold through iHome, but it's overpriced. Any good aftermarket one can be used in lieu of the OEM adapter, so it (typically) doesn't make sense to get the branded adapter.
If you are unsure if your adapter will work, check the polarity and voltage with a multimeter. It must be center positive and output 10V. The no-load voltage on a compatible adapter should be around 11V or so, but this can vary. As long as it's a 10V adapter under load, the adapter will suffice.