If you follow the IRC or IBC for that matter, you will need a total of 2 hours of fire separation, assuming it is a fee simple townhome with lot lines. If its a condo, its an hour.
CMU can get you 2 hours prescriptively and is by far the easiest until... you get to the roof. Assuming you do not have a flat roof, it is challenging to get a shell company to rake a poured beam that follows the stagger of a roof, better yet, the vault. In Florida, we have certain parts of the state that do not do that too well, and others that can do it all day. Otherwise, shaftliner assemblies are the most popular. UL U336 as mentioned or U373 (both the same) are fine. They depend on the manufacturer of the panels. Since the fire separated walls are interior, you could take the walls all the way to basement slab unless theRE IS a FEMA flood restriction. In that case, you could have a masonry or poured wall to support the first floor joists and then have the shaft liner panels attached to the top of the basement wall.