I'm using v1.5, but I don't mind switching over to v1.39.

I also posted a very similar thread in the 'Built-in Shipping and Payment Modules' about this similar topic. I think it still deserves to be posted here as I'm still deciding whether I'd like to use an add-on or a built in payment module.

I searched the forum and FAQs and unfortunately could not find the answer I was looking for. I really hope I didn't miss anything...

Basically, what's the best payment gateway to use that has the most features? I need it to at least be secure, a decent price, and it should have basic features like emailing customers their receipts and bringing them back to the site properly with a confirmation message.

This could be hosted on the Zen Cart site, or it could be hosted on the gateway's servers. I don't care. As long as it works well, is secure, and has all the above mentioned (and any other features I'm missing) features.

Also, I'm in Canada and will likely only be receiving payments from Canadian customers.

I don't mind having a few listed. That's even better!

I really appreciate the help guys.