Hello there,
Albert has invited me for your project.
I can build you Magento based eCommerce solution. Magento is the most stable solution, have a lot of features and extensions. My expirience with Magento is around 4 years, this is my primary business not an extra work.
I will build you a module to load the products from CSV and import them to Magento. I will setup a cron job on your server so the products can be updated dialy or weekly as you noted. The products that won't have any changes they won't re-import and the products that are missing (deleted from csv) they will be deleted. I will need sample from the CSV that needs to be imported.
There is a lot of Magneto templates that are good, mobile friendly, etc. I have included 10 hours work on the template to install it and modify it(simple modifications edit/move/delete), also 5 hours to explain how you can manage the store.
I will give you ongoing support for your website anytime that you will need, we can deal hourly rate about this stage later.
As you can see on my profile, all my clients are super satisfied and my feedback is excellent 5/5.