Turnkey E-commerce System Setup

I'm looking for a freelancer to source and install a turnkey e-commerce system similar to Flowlance and Stan.Store.

Key Requirements:
- E-commerce functionality is a must
- Platform should support selling of digital products
- Delivery methods: instant download and access through user account

Ideal Skills and Experience:
- Experience with e-commerce platforms
- Familiarity with digital product delivery systems
- Ability to provide a demo link

Please include:
- Demo link of the proposed system
- Cost for sourcing and installation