Hey as per your recommendations i have used www.sbb.ch to purchase my tickets from paris to basel but when i continue on the site it redirects me to uk.voyages-sncf.com/en I'm guessing its because it in english correct ? i wanna buy my tickets but i wanna make sure its from that site www.sbb.ch
TGV actually is a French train and they are now sending you to a French site. However, you may not be able to get your credit card approved, which is why I suggested trying SBB. If it doesn't work, then you're back to Rail Europe or www.capitainetrain.com.
You should almost always be buying train tickets from the site of the country where your trip originates. Since you are going from Paris to Basel, not the other way, you do not want Swiss Rail, but French Rail. That's why you would use SNCF http://en.voyages-sncf.com/en/ if you can get it to work, or Capitaine Train https://www.capitainetrain.com/en if you can't.
Use SBB to buy your tickets from Switzerland to Italy.
The train from Paris to Basel (or vice-versa) is wholely SNCF. The boundary between the two railway companies (SNCF and SBB) is at Basel station, where the train is handed over from one company to another. Up to Basel it is a "French" train and SNCF fares apply.
Make sure you get a "print at home" ticket (A PDF file which you get by e-mail), then all you have to do is print it and bring it with you, no messing around at the station. The ticket will show the departure time, date, coach and seat number.
The SNCF website is very user-hostile. Another good site, the one I use, is http://loco2.com. It is a British company and the site is in English.
another vote for Capitaine train. Easy to use, they took my US credit card with no problem.