BAHAHAHAHAHAHAHAHAAAA...this brings back memories
For those who used to be on Plecofanatics.com when it was around, im sure you all remember the massive debates that went on.
The short answer Laykoo is no, there is not. The longfin bodytype is limited to the common bristlenose, the peppermint bristlenose is a different species.
There are those who have tried to breed the two together and as far a I know they have not been suscessful. There are those who have said they have done it but they have never provided pics and as we all know, without pics, it didn't happen.
In so far as the possibility of getting one. It is suggested that all fish have the longfin gene (it is seen is some chiclids, Koi and plecos) and that it just needs to be either activated or bred into a dominant state...which is basically impossible without knowing what gene it is one or how it works.
It would be an amazing fish but alas we can only dream what it would look like