Most new tanks come with a "Pro" valve these days (or can be easily specified with one) and these allow either reg fitting to be used by means of a screw in converter, easily removed and replaced with a Allen key.
SOME first stages are very simple to change from DIN to yoke and vice versa, its a question of buying the appropriate kit and removing the one to screw in the other.
Other first stages also need a kit but the process is more involved and is not as simple to convert back and forth. If these are left DIN, then a yoke adapter can be used but as Richard said these add bulk and are not ideal. Not a deal breaker IMO but still, need to be aware. If they are left yoke, then can only be used with yoke valves.
IF you decide to get DIN first stages, then Id recommend getting the 300 bar versions, they are usable with any DIN valve and give you some additional options for some interesting tank variations. Granted, 300 bar tanks and fills are not very widely available in the US as far as i know but there is no downside to having the 300 bar vs the 232 bar once you decide to go DIN.
From your other postings, I suspect you are going to end up going down the tech route in the not-too-distant future so once you buy your own tanks I would get them with the PRO valves so that you have options. The DIN vs yoke debate is strong on this board, Im not diving out of the US so I can't weigh in on it, my experience has been overwhelmingly positive toward DIN but then Ive never had a problem getting DIN tanks to rent. My yoke adapter has never been wet in 16 years