yea the h23a1 and h22a1 exhaust are pretty much identical (exclusion muffler) from the CAT back.
the header and downpipe are different between the VTEC and non.

the head itself is different so you cant rig a h23a1 manifold/header to fit an h22a, you may be able to use the h23a1 downpipe, but i would not recommend it.

you should also get a straight pipe+exhaust+header, when u get the h22a
you should be able to pop some flame outta the muffler that way.

~boom