Come to Northway Aviation at KPAE, where Boeing builds the 787. We do the initial CFI checkride in our twin engine Beech Duchess. That way you are an MEI and within a day or two you can do the single-engine add on.
The pass rate for initial CFI is low but doesn't need to be. Study hard on the FOI, FAR's, CFI responsibilities and do not go to the 10 day schools.