I don't know if Tote delivers to Petersburg.
If you can drive your truck and boat to Haines or Skagway, you could get on the Ferry there and save yourself having to transfer to a second ferry. I think there is still ferry service between Skagway/Haines and Petersburg that does not require a transfer. You would probably save some on the fare, too, compared to taking a ferry out of Whittier, but it still won't be cheap!
Come to think of it, you may be able to get your stuff on an AML barge out of Haines/Skagway to Petersburg. I don't know, but that might be cheaper than the ferry. The practicality and logistics of your options may depend on whether you are going with your truck and boat, or just want to ship them without you.
Bill