All SVT's have 19lb injectors.
Definitely put the larger 00 SVT LIM on, but use your old fuel rail & injectors.
BTW - the mechanic is dense if he can't even tell the difference between the 2 different style injectors!

They don't even hook up the same.
However since that mechanic doesn't seem to know the difference it may not even be a 00 SVT LIM???