The real deal
If you’ve enjoyed this and want more, and a more authentic experience, there is of course the option of adding actual hardware sound modules to your setup. We’re not talking Stradivarius violins here, and while the prices of synths and samplers may have gone up in recent years due to increased demand, they are still very much around and relatively affordable on the used market. eBay usually has a fair selection on offer, though be warned that prices there tend to be relatively high as sellers are well aware that the site is frequented by a lot of collectors and vintage nuts for whom money is no object.
To find stuff at more humane prices I recommend browsing the local classifieds, places like Craigslist or your national equivalent, buy & sell groups on Facebook, and the Facebook Marketplace. Regularly visiting thrift shops, flea markets and garage sales is also a good idea. You will most likely not find anything interesting right away, but keep an eye out over a period of time and your patience will be rewarded sooner or later. If you’re lucky you’ll come across a seller who doesn’t know what the gear is worth, or doesn’t care and just wants to get rid of it, and is letting it go for a really good price.
As for whether a particular unit is worth getting… well, I’m not really an authority on the subject. I have only owned a couple of sound modules over the years (the aformentioned Proteus 2000, and a Yamaha TX81z), as I got into virtual orchestration in the twilight years of hardware. For figuring out whether a synth/sampler might be right for you, Google and Vintage Synth Explorer are your best friends. Always make sure to read some reviews and listen to sound clips before making a decision. Still, if you find something that isn’t exactly what you’re looking for but the price is really good — just get it. It might come in handy at some point, but even if it doesn’t you can always resell it at a price that better matches its actual value.
In regards to the ones talked about in this article, I would personally not get a TX16W unless I found it for some insanely low price (like $50 or less). As of this writing the only one listed on eBay goes for over $300, which is kind of steep for something that you realistically can’t do much with all on its own due to the 16-note polyphony limit. As for Yamaha XG units there are several to choose from and these are definitely more attractive in my opinion, since they are far less limited than the TX16W and can be used as a complete retro music production tool, even though they offer less realistic sounds. The Proteus 2000 might be worth getting if it has some orchestral expansion installed, otherwise I would recommend the Virtuoso 2000 instead.
Do keep in mind that unless your audio interface has built-in MIDI ports, you’re going to need a separate MIDI interface or a USB-to-MIDI converter if you want to hook up external hardware and have it communicate with your DAW.