I feed coastal hay. I wish I could get it direct from a farmer so I would know their practices but so far, it hasn't seemed to hurt my buns. Pretty sure the only hay you need to be careful with is alfalfa as it is possible to get too much calcium for older rabbits. I would be more specific except I don't know enough about it. But I think any kind of grass hay will be fine.
If you feed pellets they are usually alfalfa based so you don't want to feed alfalfa hay. Bermuda, timothy, orchard, etc are all good hay choices. With fescue hay if it contains a certain fungus I know in horses and cattle that are pregnant it causes issues, not sure if it affects rabbits the same way but I would personally choose a different kind of hay if there are others available.