I'm with Alli - can you feed cubed hay? It seems like it gets easier to find timothy in cubed form every year, so that definitely could be a good substitute. The cubes are less dusty, there's less of a chance of getting pollen out in the air.
Another thing, sometimes if you get second cut timothy hay, it won't have as many flower heads in it and will have less pollen. Whenever I use first cut or second cut that has a lot of pollen in it my husband has a terrible reaction to it.
The chins don't like burmuda as much, but it definitely is a good substitute. I use it a few times a week with my chins...we have a burmuda day and then have a timothy day. It's worked out pretty well.