Just so I am not creating confusion, I am assuming that you mean Aronia melanocarpa 'Autumn Magic' which IME is usually called chokeberry (chokecherry is usually a native Prunus or cherry tree.)

We have native Aronia that grow along the edges of our woods and river bank. They seem to not be affected by bugs or diseases, and of the three seasons of interest (spring flowers, summer berries, and fall color) I like the fall best. They do sucker some, but I don't know if the selection Autumn Magic will or not.

A few suggestions of nurseries that you might call to see if they have or can get an Autumn Magic for you:
Cole Gardens in Concord has been willing to special order for me in the past
Brochu Nursery has a pretty good range of less common woodies, often in large sizes
Lake Street Nursery in Salem has a good reputation for woodies, though I haven't been there
Scenic Nursery in Raymond has Autumn Magic listed as of last August, though their website says call to confirm.
I've found some interesting plants at Spider Web Gardens in Ossipee so you could check with them.

I know that Millican Nurseries (a huge wholesale nursery in Loudon) had it on its list as of 2007, so you should be able to get it relatively locally, either in stock in a retail nursery or by ordering it from a nursery or landscaper who does business with them.

Some other shrubs to check out that should stay under 6':
Fothergilla Mt Airy (you can come see mine if you'd like to see them in a planting) flowers and foliage, no berries
Cornus Ivory Halo (variegated foliage, fruit for the birds, red winter stems)
Viburnum Cayuga
Hydrangea paniculata Little Lamb
Ilex verticillata Red Sprite or Short Cake winterberry holly (red berries in late summer through early winter) deciduous and needs a male polinator somewhere in the vicinity
There is an enormous range of deciduous azaleas that will bloom from early spring to midsummer that will stay under 6', and many have lovely fall color as well
There are also a bunch of evergreen rhodies that stay under 6'. We have a rhodie just outside the kitchen window that robins build a nest in virtually every year, and the bees love the flowers. It often has migrating birds in its branches.
You can use the search page from the American Rhododendron Society to help you find ones you like and then check with nurseries to see what they can get for you. (the azalea search is under 'plant data' at the top of the page)

For some of the shrubs that lack summer interest, you could grow a bell-shaped type 3 clematis in its branches once it has put on a bit of size to provide summer flowers of interest to insects and perhaps hummingbirds (though I've never seen a hummer in my clematis.)

Here is a link that might be useful: American Rhododendron Society rhodie search page

nhbabs, thanks for the detailed information and correction. Yes, it's the Aronia I am interested in. Maybe it would help in the future if I started using the botanical name!

I love viburnums but I have Onandaga right now and even after cutting back it's over 10' tall. (I might have the variety name wrong.) It wasn't supposed to get that tall and is planted in ordinary dirt. It might be getting liquid fertilizer drippings from two hanging plants on shepherds crooks next to it. It was planted in 2008 and I should have started cutting it back soon than 2011. It made a lot of upward growth that year with little side branching. Cutting back seemed to encourage it to get wider so it has ended up much too big for that location. I figured I should get something that shouldn't get over 6' or maybe 4'!

I'll check Brochu again. I was looking at the Ilex but would need 2. Ivory Halo looks like a great suggestion esp the red twigs in winter. Fothergilla is on my maybe list.

Thanks also for the suggestion of the nursery in Raymond. I'm not familiar with it at all.

The huge viburnum seems to be popular with the hairy and downy woodpeckers who will stop there before going to the nearby suet feeder so I would like something twiggy the birds will like even if the chipmunk and squirrels probably got most of the berries.

Hope to meet you sometime!