joomla is rly annoying. when i worked with it, it rly made me mad, always some little bugs occured, takin hours of my life to solve it. and if you got it working, you will have a lot of fun updating it to a new release.
i think there are not many people who actually can help you with this cms here, even on the official forums you will have to be patient to get any help.
would suggest you to use magento or another reliable shop software.