Looking for a good e-commerce plugin

I’m currently looking for a good e-commerce plugin for WordPress. I have done much research and have tried multiple plugins, but none satisfy my needs. The two biggest issues I have is finding one with:
1. CSV importer that includes a picture field.
2. Shipping module that allows for custom flat rate prices (ex: $5 for 3 day, $20 for overnight, $0 for in store pickup, etc.)
Also, if the shipping module had automatic rate calculators, it would be a plus, but not necessary.

The main issue I have is the first one, and since I have over 1,000 items to add, it is a must. I would perfer it to be free, but am willing to pay as long as it is not too much and is a one time fee, not a monthly payment.

Any suggestions would be greatly helpful.