Hello,
I understand that you want a website to promote and sell your seminars. I checked the attached document, I can see that you have already researched, we can use anyone. Few of them are really very good. We will build the 3 packages of 1095€, 895€, 295€. User will signup with mail chimp integration. We will use WPML to make site working in all 3 language like Russian, Greek and English. We will integrate the paypal with it. I am looking forward to discuss further with you.
Regards,
Shouvik
Cantrip Solutions Pvt Ltd