North Creek Nurseries' description of Aster novae-belgii or New York asters/Michaelmas daisies says the leaves are smooth, unlike NE asters and there are only 15-25 rays on the flowers which suggests the NE asters have a higher number of rays. Another comment was NY asters aren't as good for cut flowers.

Bluestone Perennials sells a lot of asters so you could check out their website too for colors, heights, etc.

Here is a link that might be useful: North Creek Nurseries NY asters

A.Novi-angliae is a clumper and A.novi-belgii is a runner. Novi-angliae does not open flowers in bad weather (with an exception of 2 or 3 varieties). Novi-belgii gets mildew just because you look at it, novi-angliae is resistant to mildew(but not immune)

Just what I was looking for! Thanks.