Online Payment Processor

I’m currently searching for a payment processor to accept payments from credit cards on the internet and which keeps a balance in Canadian currency. But I couldn’t find any that don’t have upfront and monthly fee, and that didn’t need a legally registered company. Well, except for Paypal; but Paypal doesn’t seem a very safe alternative. Any suggestion?

My current idea is to go for an American company. This would keep the balance in US dollar, which means that for non-US payments I’ll incur twice the monetary conversion fee, which is rather annoying. Later, if things go well enough, I’ll work to setup a better payment system.