I'm doing a major home theater upgrade to an HD front projector setup. So I'm buying movies on blu-rays for the first time in several years. I intend to upgrade to 4k in three years when projectors are affordable. Should I be buying UHD now rather than blu-ray? Do all UHD discs come with blu-ray discs too? Are the blu-rays included full featured, equal to buying a blu-ray-only release? Or, should I save some money, buy cheaper blu-rays today and worry about UHD in a few years when I upgrade.