Welcome. The usual suspects are form, form and form followed by Z Predator, Z Force, Banshee, EXP1 (Banshee close copy out of production) and Spirit. Spirit is a meat hook and the shortest out of these but is the easiest to keep from flipping over and will fade the earliest and hardest. Force is the fastest and longest and way longer than the Reaper. Depending on your power the Banshee and EXP1 might be the closest match distance wise or the Spirit. Pred is faster and longer than those two and they are faster and longer than the Reaper.
If you drop the ease of throwing requirement a bit in favor of closeness of speed and distance then an E Blaze could work. I haven't thrown them side by side but i think the Blaze is slower and shorter with a fairly similar flight path to the Reaper.
Form bug numbers one and two i think are too much speed and rolling the wrist. Many are astounded by how far they can throw with a reach back where the front of the disc is at the same level as the right back. Almost extending the arm straight at the rip produces good distance while not rolling the wrist so easily. You want to have a quick, quick, quick wrist flick in the end of the throw followed by a long follow through on the same plane of hyzer you threw at. The thumb should point to the right not to the left once the arm has stopped. How much up or down the thumb points after the follow through depends on hyzer, flat or anny angle release of the flight.