What is the difference between the words saldo and importo? Aren't both just amounts that need to get paid? It seems like in Italian it is not enough to say quantità to refer to an amount when dealing with money. It seems like saldo is a balance whereas importo is an amount to be deposited. Is this the difference? Where can I find a dictionary of banking and business terms in Italian? Italian to English or Italian to Italian will do.
That's the difference, correct.
If it helps further, you can picture saldo as referring to what is "left to conclude the business", so for example the resulting balance of the positive and negative accounting transactions, the amount due in an invoice, or the remaining inventory that needs to be sold out in a shop (that's why we advertise discounted sales as saldi). Similarly, importo is a quantity of value that needs to be "brought", in the pockets of the seller for example.
As to your other question, you can try these out: