humane-type societies may have some contacts for you, as may 4-H or feed stores.
if your roo is very gentle, one hen may be fine (as with my roo) but if he's more amorous you may need more hens.
as you likely know, there may be health issues if you bring hens in with illness and your roo catches what they have. so learning a lot about the hens would be best.
with regard to roo food, you may already be doing this if you've had or researched roos- i feed my fellow game bird maintenance (layer is also always available for his lady friend but they both seem to prefer gbm and then she supplements with oyster shell and has perfect eggs). they also eat sunflower seed, and some daily fruits/veggies and also avia charge 2000 in their water, changed at least daily, much more in hot weather. my roo is approximately 8 years old now - happy and healthy.
all the best.
jj