MidwayUSA has 38 special ammo. At least, earlier this morning they did. If they're out, hit the "notify" button. They'll email you as soon as it gets in.
The .38 super (and .25 and .32 ACP) are semi-rimmed cartridges. The rim diameter is slightly larger than the case, but they appear rimless to the naked eye. They still headspace off of the rim like a rimmed case. Rimless cartridges headspace off of the mouth of the case.