Intercooler

I was thinking about buying a intercooler from e-bay. its alot cheaper the package deals. My questions are what is involved mounting the cooler, is there a certain way the in/outs should be? Side to side or bothe in/out in the front like the paxtons cooler? Also, is there anything that is piped (tapped) into the pipe from /to the intercooler? The discharge lin comes from the blower to the intercool, then out from the cooler to the upper intake, is that right?
Thanks

It would be air to air. Ive seen the paxton installation guide and there is a lot of parts. Is there anyone who has done this the way I am thinking? Is is more of a headache?