I need advice on an e-Commerce website.

Hi guys,
I decided to come here to get help and advice after running for several pages on google search.
I’m probably a person here that less understands about programming or building sites, but even so I was able a few months ago to make my own site using WordPress, which for me is a fantastic tool philosophy.
Well, I am now needing to create an e-commerce site. Even after reading so much about the various plugins in this area (WP e-Commerce, WooCommerce, Shopp, YAK, Cart66, GetShoped) I still can not decide. So let me explain my needs and see if anyone can help me.
Case: I created a service that will be offered in the area of tourism. This service may have initially four versions. Therefore, it is like an e-commerce site with only four products / services to sell.
I will register a new domain to create a hotsite to give information and for launching of this new service. This hotsite must show the service in 4 languages. Each language (page) will have a video presentation and text about the service. If the customer wishes to purchase the service, each page will have a link / button that will direct to the store. Here comes the first question. How to make this store in the same language that the client was receiving information about the service? If the store is on a hotsite, in what language it will be shown? Or the store must be on another site different from the hot site ?
Well, I hope to get some help.
Thanks in advance.