If you're trying to protect it from snooping family/friends or common thieves, you're current solution is probably sufficient (as long as no one else has access to the safe combination/keys and the safe can't be moved easily).
If you're trying to protect it from hackers, be sure any computer you plug the USB into is NOT/NOT connected to the Internet.
If you're trying to protect it from business associates or professional criminals, get an Iron Key Secure USB, put your data on it, and store it in a bank safety deposit box. Have an attorney draw up instructions to file with the bank about who can access the safe deposit box and what happens to the contents in the event of your death. This also might be sufficient for protection from local government officials depending on how good your attorney is.
If you're trying to protect it from the feds, forget about it.
I'm look for a very specific solution that I'm not sure exists. I would like to purchase a USB drive that I can plug into a PC or Mac (works on both) that is encrypted and of course requires a password to open. The USB should have built in software to store personal data, such as credit card account info, SSN etc., and not just passwords as most encrypted USB drives seem to offer. This is not for travel. I would like to keep it in my safe.
My current solution is an Excel file encrypted with TrueCrypt (which I intend to stop using due to recent events) on a normal USB drive.

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