Your question is so broad as to be virtually unanswerable, analogous to "I'm interested in gene regulation; which transcription factors should I use for chromatin immunoprecipitation?"

What is your biological question? In what system do you work? WHY do you want study HDACs? Which HDACs? Answer these questions, read some relevant reviews/literature, and try to formulate a more specific query. We're happy to help, but need some guidance from your end.

You will also find this post useful: how to ask good questions on a scientific forum.