Colin,
Zonal Pro warmtone would be really good, probably, because it's a very low contrast and soft working warm tone developer. Supposedly it's nothing more than Ansco 120 (not 130) that you could mix at home with the right tools.
Perhaps Kodak Selectol Soft would be appropriate too? Dektol really is a developer that produces a lot of contrast.
If you'd like to try it out some time, Amidol could be good as well, as it exhibits what I think is the longest tonal scale I've ever been able to produce with Fotokemika Emaks paper. Just stunningly deep and rich blacks and beautiful highlight modulation right at the top end.
- Thomas