You definitely don't need the latest and greatest. I do believe that windows 10 is a little more secure than Windows 7. Our laptop that had Windows 7 on it was accidentally migrated to window10, froze up and is now gathering dust. If you live near a Best Buy store, I would consider going there and check out tablets. They are very lightweight and portable. I've always found the staff at Best Buy to be very helpful.
Personally I am a fan of Apple products. I currently have an iPhone, iPad and a Mac computer. I have found them to have less problems. I believe them to be more secure and they're easier to use. The downside with Apple is the price.
If you go with windows 10 I would advise getting 4 GB of RAM to make it more future proof.