"If using payments only are there any additional tax or shipping settings?"
--- No, "tax or shipping" is purely split into ecommerce modules (I think the other ecommerce related modules deal with that, like ProductModifier class, etc). The payment only focus on payment methods and their gateways, and how generic it could be to hook up with any places where need a payment.
wow... so there isn't really an ecommerce option for silverstripe at the moment that will have an upgrade path.
I guess I will try the 2.0 branch with ecommerce as I am required to have 2 cart groups in my next project.
I have ecommerce (latest trunk) installed and running with 2.4 currently, seems to work but I am early in testing.
V2 is working in SS2.4 with the latest trunk of e-commerce.
I have been able to purchase an item with PayPal (sandbox account) and return to site (well almost I got an error due to my local server not having email configured, I think... since it appear that mysite.com/paypal/complete tries to send an email regarding the completed order.)
If this is the case can anyone confirm if notification is sent if the user does not return to your site after payment is made?
@ MatWeir, a quick answer to your PxPay question. You could check out payment-module, you could find function doDPSHostedPayment() in DPSAdapter.php which is under code/DPSPayment/ and it use some third-party code/classes in folder DPSPayment/thirdparty/dps_hosted_helper, if this is what you mean by "code implementation examples".