the fans on the PSU don't do your computer any good just the PSU. It don't cool the computer down at all. I have an Antec 900 which has plenty of fans.
just make sure the airflow is going in the right direction.
watercooling is not neccessary unless you can go really high-end. the cheap s*** will just give you grief. a high-end air cooler will work as good as cheap watercooling and you dont have to worry about leaks.
i don't really think watercooling is ever a requirement unless you are pushing some heavy-duty overclocks. but, this is a hobby and some folks like it. and it looks cool.
the fans on the PSU don't do your computer any good just the PSU. It don't cool the computer down at all. I have an Antec 900 which has plenty of fans.
Still 60C idle, 80C load? Maybe the software, you're using to monitor temps, is giving a wrong reading. What does the BIOS report, on the CPU readings?