Get 2, 4, or 5 start acme, so that it spins slower at the same speeds. My Y axis has 1/2-8 2 start acme, and about 32" of travel, and has no whip at all at 200ipm.
If you need to go faster, go with 1/2-8 4 start or 1/2-10 5 start. Both are 2 turns/inch.