Okay, so I got this laptop from my buddy for like $300 and I'm trying to figure out the best GPU I can put in this thing to make it a little more up to speed.

On the bottom is says 

"Alienware 17 Deployed August 24 2013"
"NVIDIA GeForce GTX 770M with 3GB GDDR5"
"Intel Core i7-4700MQ"
"Reg Model P18E"
"Reg Type NO: P18E001"

My power supply says
"Dell AC Adapter Model DW5G3"
"Input 100-240V~ 50-60Hz 2.5A"
"Efficiency Level V"
Appears to be 193.94 Watts.

Any help would be appreciated.