Ive used some china parts on my car with good results(1,2,3,1-now to get flamed), in reference to the pod filter i think its a waste as now you suck hot air from the engine bay unless you get a cover for it, a stock air box with a good filter is better than a pod in my mind(especially on a stockish motor).
Have a look in the forced induction threads for info, pros and cons of different gear, all your questions will be answered buy searching through there.
My performance steps
1. make it stop
2. make it handle
3. make it go