Need a e-commerce

I am an avid wordpress designer and woul love to use wordpress for everything. I have used the instinct e-commerce shopping cart before and have had some problems with it. I know they have recently upgraded it and have been considering using it……

I guess the main question I have is, what should I use for my most recent clients e-commerce system? they will have 300+ items it’s a pretty dynamic site.
You can see a screenshot here:
https://www.mbwebdesignco.com/screenshot5.jpg

So you can kind of see how dynamic it will be….This is late notice, because i need to start building it out yesterday

But any suggestions would be greatly appreciated!