All depends on how much you can justify spending and how bad you want to do it, a Dillion 550 is a top of the line press as a single stage, bottom of the line in Dillon's line. It's expandable, it's a very good product. That said , many folk who run 223 are very happy with a Lee turret press. Only thing with progressives, is watching out for what size brass they'll handle, the bigger they are the more loot, the faster, the more loot. The emphasis on the press and speed is overhyped in many ways, there are things that are far easier to do off press on a single stage than on a progressive. It also depends how far down some rabbit holes you go on what you load, you spend far more on the accessories than the press, and they are what really speeds up or slows down reloading, some tools are fine for many apps, some are not so suitable for more than a few apps. A case prep center speeds up primer pocket cleaning, crimp removal, uniforming, neck chamfering and deburring and saves a pile of manual labour on the fingers and wrist, you can even trim on them with Lee attachments, FA unit has a built in trimmer.
Some tools, like Lee and Hornady, have captive shellholders you need to buy, can't use an RCBS or Lyman or Redding on them. I think quick change die bushings like Hornady and Lee are a waste of money. Wilson trimmer needs cartridge holders. FA & Lee have some great product, also have some krap product, you can't necessarily tell til you use it. I try not to buy anything much in Hornady anymore, had some not great experiences with some of their stuff. I would not buy an FA press, wouldn't buy an lum press for anything other than auxiliary purposes, they are light duty, but, will make ammo.
I have a Rockchucker, got by fine with that for 45 yrs, splurged on a Forster Co-Ax 12-13 yrs ago, then also picked up a MEC , like all three. Just picked up a Lee C press to use for a dedicated priming tool station for a Derraco unit. Had a Lee hand press I used for reloading at the range, could use the C press for that too, it's not the greatest for full length sizing rifle cases though. MEC handles spent primers better than an Rockchucker and has a floating shellholder like the Forster.
Used a Forster trimmer for the last 45 yrs, it's very expandable, also have a 21st Century, I use 3 way cutters on my trimmers. Giraud drill driven 3way unit may well be a very good investment for a guy with one cartridge to start with.
I have a beam scale, still use it for small batches, along with a ball powder, and a Redding powder thrower, and Lee spoon for trickling. Also have a Chargemaster, and a V4 Autotrickler on a FX120. Also have a 35 yr old elec scale I used for weighing bullets, brass, arrows, other misc stuff---not powder. My 223 and 218Bee get done on the beam & thrower, ball powder only, the rest, anything with stick powders, get done with the V4 or the Chargemaster, still trickle with a Lee spoon if necc.
For myself, with new brass, I uniform primer pockets, clean with either an RCBS brush or the uniformer, chamfer--- all on a prep ctr, size on either the Rockchucker or the MEC or the Co-AX, use Imperial Die wax and dry neck lube for all of my FLS sizing, dry neck lube for neck sizing, mandrels. I have a dry media tumbler if I feel like I want to use it. I used handprimers for many years, RCBS universal is OK, or the shellholder version for stuff that universals or Lee shellholder style won't handle, FA has a decent handprimer. Derraco has an on press priming tool that is really nice to use, better than any other make or style I've tried, tried nearly all of them.
I use predominantly Forster dies, also have a few Reddings, and some RCBS. Used Lee and Hornady and CH4 and Lyman, use some Lee, mostly for cast bullets. Lee and Lyman are the best for cast bullet tools, RCBS is fine too.
Do some diligent research before buying your stuff, look at some vids as to what works and what doesn't, why folks do certain things, look at complaint vids and threads. Sometimes there are better alternatives, sometimes you can avoid pitfalls.