Can you give me more details, like what happened when you installed a mobile plugin? Did the mobile plugin not load at all (when accessing the website from a mobile device) or was it showing some other errors?
If you have tried both WordPress Mobile Pack and WPTouch and didn't work, then it might have something to do with your theme (especially if it was customized) or existing plugins.
Yours is an e-commerce website, so I think the best way to go mobile would be to use a responsive theme. I just accessed your website on my phone and it's true that it has some issues when displaying on a small screen (mostly it looks like the theme was not customized properly), but I think it would be much easier to fix those issues than start from scratch with a different theme.
Overall, WordPress Mobile Pack 2.0 is intended for publishers / bloggers and displaying articles, so it would not be a good match for you.