I need to create a Canadian lawyer's trust account report with transactions for each client & their current balance.
That should be pretty straight forward. Assuming the trust accounts are not physically separate bank accounts, but logical money tracking within one bank account, you can simply create accounts under your chart that are sub-accounts of the master account. This way you'd end up with "Trust Main Account" with "client name 1", "client name 2", .... sub accounts underneath it.
Then, when you run the transaction report for the account, simply tell it to summarize by sub account and you'll get the list you're after.