Hi Jimmy and thank you for the reply.
Basically, I need to change shipping options to my local canadian shipping company, taxes needs to be changed as well (having a federal tax and provincial tax, and US tax) depending on my customers where they are from). And last, the payment method (other than Paypal and the rest of the methods Powerstore offers). I want to be able to have Credit Card payment method. These are the main features and there are some other little details I need as well.
Now that you mention, I need to know (I am not a PHP programmer at all) what, how, and where do I need to make modification so that Powerstore will not be affected and non functional (at least if you can guide me for the shipping, taxes, and payment method).
Also, I wanted, initially, to know how do I install ecart in a way that it will be connected to my existing powerstore online store.
Hope to hear from you soon.