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If you want to start an online business with B2C module then this is mandatory to integrate Payment Gateway in your portal so any customer can make payment of booking amount easily.
No, savings account can be connected with payment gateway if the company type is sole proprietorship.
For start up you should go with a payment gateway which provide good support, easy to register and fulfilled your requirements.
In white label B2C portal we have 10+ gateway options - Pay u, CC Avenue, Atom, Rozar Pay, Paytm, Paypal, AgreePay, CashFree and AmarPay. You can register any one of them.
Payment Gateway transaction charges are depends on your payment method and your turn over. You can discuss with Payment Gateway provider and check their offer.