Of the two, I would probably get the RevHard. The GReddy SOHC comes with a smaller turbo and is pretty much bare bones(no ic, no bov, fuel management is a joke). The RevHard, while it costs like $1000 more is pretty complete, and comes with a larger turbo(T3/T04B or E, I forget), ic, bov. The only aspect in which the RevHard kit might be considered less complete than the GReddy is the downpipe. RevHard realizes that a lot of people have hybrids, custom exhausts, or other constraints that limit how their downpipe can be routed, so they provide you with a half-complete downpipe. It basically goes from the turbine down to under the oilpan. Then, you can add a flex section and whatever flange you want. The RevHard kit comes with a 12:1 FMU and an inline pump, which is adequate for 7-10lbs of boost, but not really the ideal setup. It's still better than the GReddy fuel management setup, though. The GReddy kit is a good street setup, with its quick spool and great fit. Its weaknesses are that it doesn't come with a lot of the components that are almost mandatory with a turbo setup, and that the cost of adding these components pretty much makes up the price difference between it and the RevHard kit. The Revhard kit, is generally complete, with the exception of the DP, but there's still room for improvement, especially with the fuel management components. The RevHard kit's larger turbo is good for more overall power, but will suffer more lag than the smaller GReddy/Mitsu TD04.