Just a different take on your question - using 6x9 negs, grain may not be all that important, and if there is a lot of activity, you may want more speed either for shutter speed or depth of field. If in your position, I would use Delta 400 with HC110, rate a bit low to pick up shadows, and hold back agitation to manage highlights. This combination with normal development gives me 16 x 16 prints with really not noticeable grain. But Rodinal would work well with it too, same agitation strategy. I use Rodinal 1:100 with this film in a semi-stand method, which produces very manageable contrast.