I am assuming you have a 2nd that you want to combine?
You cannot refinance into one loan if you are upside down. Even if you were eligible for the HARP refinance, the 2nd would have to be resubordinated.
If you don't have one of the 4 mortgage types you listed then refinancing an upside down mortgage is not going to be possible at this time. Rumors of HARP 3.0 are out there and that may help so stay tuned.