Tigranpetrosyan,
I can update your current store and also FREE i will install a premium template on your store. I have on my own from previous stores some premium theme than i can install for you.
It includes slider, mobile store (to be viewed on mobile devices), featured products, custom logo and others.
Im your best ALL IN ONE solution, also i'll give you post installation support if you work with me. MY experience is more than 60 prestashop stores installed.
Send me an email to: suarezweb [at] hotmail com
Best regards