I am using Magento 1.9.1 CE with Ultimo responsive theme 1.14.
I need to get extensions that are compatible to Ultimo theme:
- One Step Checkout
- Ajax cart
- Ajax login
- Newsletter pop-up
Please let me know the extensions of paid and free.
What payment methods do you currently have? Not all provide good support for a one step checkout.
Payment mark - is that part of the Paypal module?
The one that is best supported is: http://www.onestepcheckout.com/ - at least I see it mentioned in all payment modules we use. They also have a responsive design that works very well, placing all columns below eachother.
One I don't recommend is MageStore OneStepCheckout. It's horrible code and upgrades don't improve the situation (some vendors you see they learn from feedback over time - this one doesn't).
If you choose to go with another, first check the money-back guarantees and if you have ample time to test it within the period the vendor specifies.