also what is the difference between the cyclone engine and the regular usdm 4g63??
Essentially, they are identical. The block and head are no different whether they are US or JDM motors. The "cyclone" refers to the dual runner intake manifold that is vacuum actuated and uses a short runner at low rpm to help out with low end torque and then switches over to long runners at high rpm to help with top end torque. Some people opt to wire this up, and keydiver sells a chip now that helps activate this intake manifold properly without having to do as much wiring (check out
www.dsmchips.com). Others just swap over the US intake manifold for ease of installation. There was a thread on here a long time ago with flow tests for each of these manifolds and the JDM manifold flowed like ~2-3 cfm more than the US intake manifold so they are essentially identical when you are talking about which one makes more power. Once again, your choice on that one.
The only perk for going with a JDM motor is if you find a Galant RS or EVO 1-3 motor. These motors come with yellow top injectors that are rated at 510cc/min. In addition, they come with a big16g turbo instead of the smaller 14b. To identify the turbo, look inside the compressor housing, if all the wheels are the same size, you have a 14b. If the wheels alternate in size (big, small, big, small, ...) you have a 16g. The EVO motors are 7 bolt from my experience and the heads are similar to the 2g in that the ports are small. I think the Galant RS has just a big16g turbo whereas the EVO motors come with the EVO big16g, which has a slightly larger compressor wheel, but I'm not exactly sure about that one. Hope this info will get you at least somewhere with what you want to do.
In short, don't pay extra for a JDM motor because it is "JDM". US motors are essentially identical and you don't get any additional gains from a JDM motor unless you stumble across the rare motors with the 16g turbo. Good luck.