[mosc]

You absolutely can.

96Accord's just pointing out (rather vaguely) that the SPT cat back uses the stock-like doughnut flange where most other cat backs use an aftermarket-like flat flange. Thus when/if you get a downpipe it will likely have a flat flange and cause you to need an adapter made.

muffler shops make adapters a few dozen times a day and charge very little money for it. It's really not that complicated a problem to address.