This is what we do and it seems to work. We use a "Check" to pay the bank statement in full each month.

Payee: Bank of America          Payment Method: Bank Acct-Checking used to pay Bill

Then we write the check like this.

   Line1. BOA-Account (positive amount of total charges for month)

   Line2. BOA-Account (negative amount of total charges for the month)

   Line3. BOA-Card1 (positive amount of total transactions for this card for the month)

   Line4. BOA-Card2 (positive amount of total transactions for this card for the month)

I have this as recurring each month and then I just have to go in and change it to the correct amounts for that month. This way I don't have to do journal entries to move transactions around.