Change efi or change intakes????

I was thinking of going with the fitech due to the fact that I also would like to start using a little spray, my ez efi doesn't have that ability. As you say they claim that vacuum isn't an issue but I'm thinking the same, change the intake first.
On the other hand I have people telling me that I will lose performance with a single plane because my build isn't high rpm. The guys that are telling me this are expierienced builders but not so familiar with tbi.