Foxconn does not make CPUs. You probably have a Foxconn motherboard.
Power ratings are different for each build, as each build uses different hardware. The only way to know your power requirements with any certainty is to measure it.
There are power calculators on the web that can give you a ballpark estimate, and that will certainly help in planning, especially if you don't have the tools to measure the actual power draw.
It's very likely you could use the existing hardware, if it will meet your needs.