There is no such thing as the Strike Nav path anymore, the new consolidated CSO training school down at P'cola has drops just like UPT. Unless you're Guard/Reserve going in, you have a competitive shot at dropping anything the AF has CSOs on (Assuming you pass the FACT).
General SA: Suck it up (STS) and roll with it, I don't think proactively dropping a Pilot slot because you're afraid you won't get T-38s or can't go to ENJJPT is going to win you many friends. A lot of people go into UPT wanting a T-38 and end up not wanting them by the end of Phase II. Same token, you can go to CSO school, ace the program and still not get F-15Es if you happen to have a class drop that doesn't have any.
Good luck