Alta does made a Neutral developer. Not bad, but we use LPD or Ansco 130.
Edwal SUper Platenium is very interesting stuff as well. Years ago I ran some test with it and with some papers it was warmer than the warm tone developers (Atla not included at that time). I don't remember the dilution ratio but I do remember the results. The Neutral were very nice, but ended up with using the other two for the highlight look.