The following companies are listed by the PA Hort. Society as retail mail order sources for Red Chokeberry (Aronia arbutifolia):
Greergardens.com
Fairweathergardens.com
Forestfarm.com
Beavercreeknursery.net
Tripleoaks.com
There are a number of wholesale nurseries in your area (NJ,PA) that list this shrub. I'm surprised that local nurseries don't carry them.
Rb

I purchased a very young - about 18" tall - red chokeberry from Bowman's Hill wildflower preserve 3 years ago. I planted it near the house to nurse it along. Now it is spreading and strong and ready to be moved - does anyone know how much light and space it needs? I have mostly part shade, one side of the yard is a woodland edge.

Have observed them in their native habitat, full shade and partial shade(morning sun) and in full sun. The ones in shade have flowers, but few or no fruit. (My experience in the garden, also.) Those that were growing in full sun were loaded with berries. BTW, birds don't eat them. It is a medium sized, suckering shrub and the largest I've seen is about 5-6 ft. tall. Very attractive in groups when the berries ripen. Mature plants can become quite leggy, not a problem for me, as I have them in a woodland, but if they are grown as a specimen plant, you may want to under-plant it(them) with a low growing shade perennial or grass.

Don't know what part of NJ you're in. It was kind of far for me, but I ended up buying an Aronia arbutifolia "Brilliantissima" at the NJ Botanical Garden Sale this spring. This time of year and even more around spring there tend to be sales sponsored by various arboretums and garden clubs. I think they tend to have more natives than most nurseries (some good advice I got from people on GW). I think I also saw one at one of the larger nurseries in my area (it might have been a different native shrub I had been looking for though) even though they donÂt specialize in natives.

I know there are fall events at the Morristown Arboretum and at Rutgers. Probably many other places too.

I heard the birds eat them as a food of last resort. I wouldn't know, because mine never has berries :-(