How do I calculate what the TOTAL Wallet fees are going to be with Bitcoin-Qt v0.6.3?
The fee will change with time, if it happened to be high due to the coins being recently received.

There is a fork of the client that doesn't require any fee to be paid.  Your transaction will just take a day or so to get any confirmations.

You can wait to let the coins in your wallet age and then at least the fee should be small and consistent.