lower budget: Invert/Empire too
mid budget: Empire scion
high budget: Prophecy z2 or rotor.
probably seem like an empire fanboy but IMHO they make the best hoppers. at high end i own both a rotor and a z2 and i'd personally say that if you are willing to compromise on the ease of disassembly/reassembly by going with a z2 over a rotor, you get way more features (lighter, auto antijam, ripdrive, interchangeable speedfeed, cheaper). Rotor's only advantage is simplicity.