If you have not already started with the Jewish Gen (www.jewishgen.org) JRI-Poland database, that's where I would start. If you are lucky, there will be records going back to the early 1800s for your town and maybe even further back.
Learn about the town? How many families lived there? If it was a small town and your family was there for 120 or more years, then you will be related to some or all of the families who settled there early. I make projects on Geni for towns and areas that my ancestors came from and start learning about ALL the families. The pattern is for rabbinical families to marry cousins and other rabbinical families, so I learn about all the families that mine married with.
I would consider DNA testing also. There just are not records for most of us Ashkenazi Jews to trace our ancestry and surnames are very new. I would do first Y-DNA and then an autosomal test. Look for others who have shared DNA segments with you over 10 cM who are from that town or towns in the vicinity. That may give you additional surnames to consider.
I am a Rubenstein by the way (Volhynia Gubernia, Ukraine) and there is a Rubenstein branch of the Alperovich / Heilprin family. There is a project on Geni about the Alperovich.