I know CT would probably tells you otherwise, but generally speaking, you stock struts would last a long time with TRD
springs. These springs only lower the car aproximately 1", and they are not as stiff as Sporlines, H&R, and other aftermarket springs.
If money is not an issue, it is a good idea to change the spring and struts at the same time. You would have smoother/tighter ride. Also, you wouold save on installation cost and alignment cost.