SLI/Power Supply question

Hi. I have a question regarding an SLI configuration and an ample enough power supply for it.

I've been told by two individuals at a computer parts outlet that I should be ok, but wanted further input.

I am looking to get these two eVGA GTX 460s;

http://www.memoryexpress.com/Products/PID-MX29653(ME).aspx

I currently have this power supply (Corsair TX 750W);

http://www.memoryexpress.com/Products/PID-MX18779(ME).aspx

Do you folks think I would be safe with this configuration?

I currently have one BFG GTX 275 768MB OC, 6GB of RAM, Core i7 920 @2.67GHz, Seagate 500GB HDD, and Windows 7 64bit Home Premium - in an Antec 900 II Gamer case.

Also, is it worth it to upgrade to this? Or would one EVGA 1GB be sufficient? The SLI 460s seem like a good deal, especially with the lifetime warranty from eVGA.

Currently game at 1920x1080. Thoughts and opinions are appreciated,

Thank you.