Dan,
Pretty much the same on this end. Was an old Casio workstation (arranger) user. Software was included as well as Cubase 3 later on as things progressed. The Casio had it all for its time: intros, endings, one-finger chording, etc. back in the day... very similar to Yamaha today.
Purchased a Roland VS-2480 with 4 expansion boards for mixing and mastering. Added keyboards and modules as I went along.
Never concerned myself with purchasing a controller, simply because not all units could be bought as modules, so had to buy keyboards and most keyboards can be used a controllers. Keyboards take up room, how many keyboards can two hands play at the same time anyway? I currently own 4 that I use and intend on keeping.
Bought a MOTU MTP/AV that could handle 8 midi ins/outs simultaneously (and could sync video) to mainly use a PC for creating and playing multiple midi files. Also sometime during the same time period, updated my Casio keyboards and purchased a Korg TritonLe.
Wanted an 88 keyboard with good piano feel, so purchased the Roland FA-08; the 1st real opportunity to purchase a good module instead of a keyboard (Integra-7), :sigh: and I didn't do it.
Needed something to integrate the audio routing of all the keyboards, DAW and VST's, and the VS-2480, so purchased the 32 channel (32in/32out) MOTU 896mk3Hy i/o interface.
Wanted the best sounds currently on the market without having to upgrade my 10 y/o computer [and didn't want to mess around with latency!], so bought the Genos.
Casio, Korg, Roland, and Yamaha all sound good, and each has their own particular sound. When assigning parts to each keyboard, the overall sound of "the band" (or, orchestra) is quite impressive. Any one of them alone (yes, even the Genos) sounds whimpy compared to real instruments. What is important is the cleanness of the sounds, and by removing onboard effects I have that.
One thing I didn't mention, is that somewhere along the way I bought one of the first midi guitar "hookups" the Axon and the module, the TC-Helicon Voicelive Rack for harmonies and GSP1101 for guitar modeling and effects, and a Yamaha WX5 wind controller.
To add insult to injury ([PC-based]), I added the audiophile/everything version of PGMusic's BIAB to the mix with "live virtual real-life" pseudo players. Probably somewhat "great" in their own right, but totally missing the human feel when mixing them into original music and scores.
I guess that is it! That's my story and I'm sticking to it (mostly). I'm sure that with 'some-timers' there are details and timings that I have missed.
Pretty much any keyboard will do as a controller, but a dedicated controller with good software will shine (as a controller). The Roland FA line is marketed as a DAW controller, so it depends on what you are looking to achieve.
Edit: I am afraid that finding "the best" sound (ymmv) is the most expensive component of the system. :sigh:
My Recommendations:
I highly recommend the Genos if you need Woodwinds or Brass and/or an overall "good" arranger.
IF you are looking for something "on the cheap" (more voices) I recommend the following:
https://www.spitfireaudio.com/shop/a-z/bbc-symphony-orchestra-discover/
For 49 euro/usd or FREE, It won't eat your PC for lunch, add a huge amount of latency, or even take up much room... (highly recommended).
If you are looking for something more along the synth route that will help you out have a look at Unify:
https://pluginguru.com
Unify will help you keep a light footprint while integrating your "soundscape" and new features are being added weekly.