Unless your already heavily invested in 3rd party SSD's, I would recommend moving to Apple/Samsung SSD's for PCIe equipped (Mac Pro 1,1-5,1) machines. If using the SATA Buss for conventional 2.5" SSD drives, you can go with
Anglebird drives. They report Apple SSD to the OS and are very solid drives with Trim enabled out of the box.
I have one 840 Pro drive booting older version of OS X and TrimEnabler. It's working for also, but I too prefer having Trim support out of the box. Just a matter of choice, not looking for an argument.