Don't cut and splice cables. If your PSU is a standard ATX PSU then it has a C14 receptacle and the plug on the PSU end us is a C13 (C13 plug in C14 receptacle). The outlet pictured is a NEMA 6-20R so you need a NEMA 6-20P plug on the outlet end. Put it together and you need a cable with a NEMA 6-20P on one end and a C13 on the other end.
http://rackmountpdu.com/Category/108-6-20p-to-c13-power-cables.aspx
NEMA 6-20P is 230V @ 20A max. You can (assuming outlet and rest of house wire is up to code) safely pull 230V * 20A *0.80 derate = 3,680W.
Note there are likely better/cheaper brands but that should get you started. You want a NEMA 6-20P to C13 cable. Of course this information is provided as is and assumes the house/outlet is wired properly and has been properly explained in thread.
http://rackmountpdu.com/Category/108-6-20p-to-c13-power-cables.aspx
NEMA 6-20P is 230V @ 20A max. You can (assuming outlet and rest of house wire is up to code) safely pull 230V * 20A *0.80 derate = 3,680W.
Note there are likely better/cheaper brands but that should get you started. You want a NEMA 6-20P to C13 cable. Of course this information is provided as is and assumes the house/outlet is wired properly and has been properly explained in thread.