I don't see any reason for it. Use Express Checkout.
You will have to use paypal direct payment local checkout in the checkout wizard, then just remove the checkout form associated with direct payments and leave the express checkout buttons.
That will have all of the advantages of paypal standard (no monthly fee), and none of the drawbacks (won't have to struggle with IPN).
Express Checkout requires that the customer has or signs up for a PayPal account, there is no option to pay by credit card as there is with a "normal" paypal transaction assuming that you have PayPal Account Optional set as optional under Website Payment Preferences in your PayPal profile.
To me that presents a significant barrier to purchase as it has been shown that a significant number of customers will bail at the point of purchase if registration is required, there is a good article called The $300 Million Button which talks about exactly this problem.