I haven't used them yet, but PinkyParadise seems to be really popular. Depends on the shade of red you want, but four lenses I was considering for my own cosplay are: Vassen Dolly Plus Red, Super Pinky Bright Red, Venus Eye Wine Red, and the Vassen Ruby Red. They are all prescription, and there's links on each of the pages to customer pictures on their Facebook page, so you can see how each lens really looks in real life.
F! Ardyn Izunia - Final Fantasy XV Done!
Anime Expo 2017