Tony,
You want a "Universal". There are two models: Universal and Progressive. The Progressive was first, and was designed exclusively for .38 Special. The Universal came later, with design improvements to allow different case head sizes, not only in the shell plate but also the surrounding portion of the press. And also versatility in the priming system.
Once you have a Universal, then it becomes a matter of choosing to set it up for small or large primers (by changing the primer slide, primer punch and its bushing), and calibrating the seating depth with the rod that actuates the primer mechanism (from the tool head).
Then select your caliber, and acquire a shell plate and dies. If you can't find old stock, then Dave Wilson (fc60) makes fabulous dies and Richard Daniels (barreltester) makes shell plates (and more).
After dies comes the powder mechanism. A variety of old stock fixed powder slides, new adjustable slides, and bushing-based slides are all available. As you will learn, there are proponents of each; the trade-space is essentially the ease of initial calibration versus the potential for drift. (I have one of each, fixed, adjustable, and bushing.)
Finally, after satisfying the essentials, you may want to accessorize. A Hulme case feeder is a delightful addition; see the "Dating a Star" thread for details, but Universals prior to the mid-50s were not tapped for the case feeder. Of course, it can be done after-the-fact, but this is a convenience to watch for as you shop for presses.
Another helpful accessory is an automatic indexer. These are wonderful for production volumes, but they do complicate the otherwise-trivial tool head (caliber) changes, so you'll need to consider that for yourself.
Good luck!
