Overprovisioning is not necessary if your OS and filesystem are sending the TRIM command, and you don't fill your SSD up all the way with data. If you ever do notice that your writes are slowing down and you find that the SSD is nearly full, then just delete some files (say, so that you have 20% free) and empty the trash so that TRIM commands are issued, and the write speed should return to optimal.
Also, OP only ever really helps with write performance, and if you are primarily gaming, then you will be mostly reading.