Hey... the guy is selling disc brakes with the trailing arms. What he's saying is that instead of buying a complete trailing arm/disc brake conversion when he did his conversion... he only bought the discs with hubs and installed those on his trailing arms. The trailing arms off a disc brake or drum brake setup are the same so it really doesn't matter. If he's offering them at a better price than go for it.
Note that all rear disc brake setups from integras and civics from 1994 + will fit your car. You could even get disc brakes from a del Sol... but to install them you'd have to reuse your civic lower control arms since the del sol ones are too short.
Something else you'll need is the proper disc brake proportionning valve. I believe the proper honda disc brake proportionning valve has 40/40 written on it. Personnally, I just went with an adjustable proportionning valve when I did my conversion