Well, Amon can do very well at that sort of level with a strong skew list, but I really couldn't recommend him for a beginner. He's both quite finikity, he's very prone to assassination, and his ideal lists mean getting a bunch of lights that are usually only used in a few lists (they're not as generalist options that can be more easily thrown into any list). Don't get me wrong though, he can be a good caster, and in the right circumstances can steamroller opponents, he's just not someone I'd recommend for beginners.
Now, for Reznik, he's a hell of a lot of fun, and pretty beginner friendly. He's not our most competitive caster, but he's solid, and plays a fast aggressive game that keeps the action high. What you have there is certainly a viable list, and I think you'd have fun with it. You do have a small number of heavy hitters though, so high armour lists won't be a problem for you, but if your opponent has a significantly better threat range than you, you might run into troubles. I'd generally take a second jack (A crusader, or even a Repenter or Dervish) with him and a cheaper infantry unit, like max
TFG.
Oh, and one other thing about Reznik... I played him just last night, and he destroyed an undamaged Galleon colossal in a single round by himself. There not much else in the game that can do that