There are several. Karl Foerster, miscanthus (many varieties), korean feather grasses.

Before you choose any, discuss how tall do you want the grasses to be. Miscanthus normally grow 5 - 6 ft on average although it has varieties that fall to around 3 feet. They produce flowers in Sept. Great sculptural plant. Huron Sunrise, Graziela, etc. are tall varieties. Morning light are shorter.

If you don't wish the plant to be that tall, then choose either karl foerster or korean reed grass. (3-4 ftt)

Other grasses that are short - choose blue fescue. Hakonekloa (japanese grass)

All that I have described are perennial types. There are annual types that you can experiment with too. Like the Fountain grasses, stipa (pony tail grass), Mexican maidenhair grass, quaking oat grasses, etc

My neighbour has a clumping grass and wants to divide it...any ideas on how to divide? We just can't seem to get a shovel through it! Three different neighbours have tried. LOL.

Small and medium sized grasses can be divided with a knife or narrow-edged trowel. A sharp, steel-alloy spade is necesary to divide the larger grasses. I think "sharp" and "steel-alloy" are both key words in this description. A section can be cut with the spade and removed for planting elsewhere. Usually a mature grass specimen can not be dug out of the ground all in one piece.