What should i use for secondary injectors?
 

87rx7 13bT atkins streetport. What should i use for secondarys? And do i need a fuel controller such as piggy back or standalone to make the injectors work properly?

12AT injectors can be 800 to 850cc from memory, they're a straight fit into a 2nd gen fuel rail, but I am sure there are other aftermarket injectors that would be a straight fit, or close to, as well.
As far as I know you will need either a piggyback or even better, a standalone engine management system.

720cc are most commonly used. Piggy back is not necessary, but a big plus.