Re: JB jr or Hotrails?
JB jr does sound like a JB. I have a neck/mid in the middle with a JB trembucker at the bridge and they are quite similar although the jr has less output.
Hotrails is hot, middy, tight, and has a slight rolloff in the top end. I have done spinasplit on it, and the single coil sound is similar but less output. I have not tried it in parallel, which might be OK for the blues and funk.
If you were only doing metal, hotrails would probably be more output and better palm mutes, but JB jr will do better meedley-meedley-meedley leads above the 12th fret on the high E string. JB jr will do better with the blues and funk.
Edit: PS welcome to the forum.