Powering 11 x 10 watt LED array
"Can I use a PC PSU?" Yes, make sure there is a load and you are connecting the signal lines properly (this information is readily available on the internet)

"Is it a bad idea considering its not constant current?" Yes

"Would this setup work or would it burn up the LEDs?" It would work fine as long as you don't exceed the ratings of the LEDs

"Would there be a better way to wire or drive this?" Yes

"If so what kind of a driver would i need?" A constant current LED driver: https://www.google.com/search?q=constant+current+LED+driver#q=constant+current+LED+driver&amp;tbm=shop (assuming you are not willing/able to build a circuit yourself)