But today is your lucky day, friend.
- Find your PCSX2 INI directory
This is the same place your memory cards are by default, just up a folder. PCSX2 1.4.0 called it "inis_1.4.0" instead of "inis".
- Make the INI file
Or you've made it before, have it already because of other reasons, blah blah blah. Skip this if you already see "PCSX2_keys.ini" in that folder.
Right-click! Make a text file! Call it "PCSX2_keys.ini"! Ignore Windows telling you you're a bad person for renaming the file extension!
- Choose a new keybind
Let's open up that nice lil' "PCSX2_keys.ini" and add a new line, starting with "Sys_Suspend="
Now, what key do you wanna use?
There's a fancy-dancy PCSX2 wiki page on how some keys are written(and other things you can change from their defaults), so check that just in case. :)
- Open PCSX2 and bask in your glory