Best Fast Scalable Ecommerce Platform - Suggestions required

We are currently on CS-Cart platform with 10,000 unique visitors daily and we expect this to go up to 100,000 and more in the next few months. We have only around 600 products in our catalogue. Due to lack of developers for cs-cart, we would like to move on to some other platform which has a larger pool of developers available and something which will serve us for at least the next 5-7 years so that we can invest money in the right code development and infrastructure.

Things we are looking in our next platform are :

- Fast and lightweight.
- Scale quickly and serve tons of customers without getting bogged down ideally with support for some high end caching systems (We are ready to invest money on good hosting).
- Availability of extensions/addons for future growth and enterprise level automation and inventory controls.
- Great product options, attributes and option combination functionality (cs-cart is excellent in this regard).
- Easy availability of Developers (we are actually looking for someone who can join our team).
- Highly Secure or something which can be secured with some best practices.

We have taken Magento out of the equation due to the high cost and timelines for development. Moreover due to the heavy resources it requires, it suffers in speed even on good hosting setups.

We are getting torn between Drupal Commerce, Woocommerce and Prestashop. Can anyone recommend the best one among these 3 that will tick all the above boxes?