There are DL (dual layer) disks that you can buy but they are quite a bit move expensive then SL (single layer) disks. Verbatim is the only brand that is recommended. I’ve never tried a -R dual layer, is there some reason you can’t use +R DL? If you need free ripping software take a look at DVDFAB HD Decrypter, it’s the free section of DVDFab which comes with a 30 day free trial period. You can use SL disks with some quality loss (depends on the size of the movie) if you “shrink” a large movie with DVD Shrink or DVD Rebuilder before burning. There are other free ripping programs like DVD Decrypter, but it can’t handle the newer encryptions, also there is one called DVDSmith.