Default Tax (GST & PST) for each Contact

I would like to suggest a change that would help me be faster at entering transactions.  When we setup contacts we can currently setup what default income and expense account they use.  Could you also give a choice for taxes (GST/PST...)  as well.   For example.   If I enter a transaction for Canadian Tire purchase I know there will always be "Both" taxes.  GST & PST on the receipt, or Construction Fasteners will always just have GST....  Both of these purchases would go under the"small tools & hardware" account.   I would like that to be a default setting for each contact that I could choose in the contact setup.