Welcome to the board, please ask any questions you have, there is a ton of experienced DH divers happy to help.
Since you are not yet certified, this is what I would suggest.
First, get your OW cert from a good instructor and learn modern diving. After you get our cert, do some modern diving....which you could do with older single hose gear. SP MK-2, 5 and 10s are fairly inexpensive and solid regs. Or find a USD/AL Conself or Titan. They are basically RAMs in single hose form. If you are diving DH, sooner or later you will want to service them yourself, starting with a Conshelf or Titan is a good way to get familiar with the USD/Voit line of regs. If you are going to be buying a BC, keep DH diving in mind. Modern BC's don't play well with DH regs (any DH reg including the AK, a little research will reveal why ) but a BC designed for DH use (Bryan's back plate and wing are a perfect choice ) work perfectly fine with a modern reg. If you run across a older kit with say a Conshelf and a good BC for a good price, nothing wrong with starting with that but if buying new, you might as well get something that will work well in both worlds.
Next find a great buoyancy instructor and take one or 2 buoyancy classes ,different classes with different agencies is not a bad idea, hopefully one of them will be a great instructor. Great (not just passable ) buoyancy is critical to DH diving since almost none of the DH regs have LP ports so you won't have a BC to depend on. Once you get comfortable modern diving, I suggest you start practicing your buoyancy skills with full modern gear but with a vintage mindset. What I mean by that is this, kit up normally but try to dive without using the LP inflator- hooked up and ready to go but just don't touch it. Strip all the air out of your BC and do the entire dive with PROPER weighting (which is sadly never really taught) and breath control (again, never taught) . Most modern divers don't believe it can be done, I actually had an instructor tell me it was not possible to dive without a BC....I so love buzzing his OW classes with a DH reg and NO BC. If things don't go well during you vintage simulation, you can always revert to modern diving and sort things out. Once you feel very comfortable diving this way, you can move on to a DH reg. This is another reason to use a VDH BC, you can simply remove the bladder, dive it old school and still keep familiar feel.
Between now and then, take the opportunity to learn as much as you can. read old post here, read old diving books, study the service manuals of any and all regs. There are a few good videos of DH diving on youtube (and some BAD ones ) . The Seahunt remembered videos in Silver Springs are a great example, most of the guys and gals you will see in those videos are members of this board. ....Oh, and no there is not nearly as many knife and speargun fights in real vintage diving.....but there are times.