Ilford seems to have you covered with HP5+ and Delta 400 and Delta 3200 films in 120 size. I'm just shooting them in 35mm for now.
Ilford doesn't really recommend shooting Delta 3200 under 1600. You can shoot it from 400 to 25600 but they recommend 1600 to 6400. Delta 400 and HP5+ 400 are an easy push to 800 if you need to push them at all, one stop isn't much for underexposure really.
I've been shooting a bunch of Delta 3200 at 3200 lately and developing it in HC-110 because it is cheaper and more readily available to me than DD-X. HC-110 for $15.99 16oz at dilution B 1:31 develops 63 rolls, DD-X 1L $19.34 used at 1:4 makes only 20 rolls which is 4x more expensive; even using HC-110 at Dilution A for 3200, DD-X is still 2x more expensive. However, I may need to try a litre of DD-X to see if the grain really is better. I also have some Microphen powder to try once I finish up the HC-110 though it also seems expensive unless you reuse the developer and replenish or up the times which doesn't sound like a great idea for long push processing runs. I have a 2.5L packet but I may get a or 1L as I could just run 4 rolls through it, I don't shoot enough to have 3 developers mixed up at the same time for side by side tests unfortunately.
Yes, Delta 3200 it has obvious grain though I like it. If I don't want grain I'll shoot Delta 100 though Delta 400 at 400 is also very good. 3200 negs seem a little thin at the recommended (everywhere but on APUG) 3200 development time of 8 minutes in dilution A however and most people tell me to develop it for 6400 (13 minutes) if I shoot for 3200 which makes me wonder how fast the film really is. I have two rolls shot at 3200 ready to go in dilution A for 13 minutes and I'll let everyone know my opinion. If I get a chance to try DD-X I guess I'll have to try developing it at 3200 and 6400 recommendations there too.
I just developed a first test roll of Delta 400 shot at 1600 last night but unfortunately I haven't had time to print it yet. The negatives look very good but the proof will be in the prints. It was an easy push to 1600 for 13 minutes in dilution B of HC-110.
I'm also shooting at roll of Delta 3200 at 1600 right now for comparison. I'll see how the grain, shadow detail, contrast and so on compares between the two.