As this is BIFL, at a significant increase in price, I’m a fan of Concept2 products. It’s a good company, making good products. As far as I can tell, they sell all the parts for their equipment going back 30+ years. I personally have over 6 million meters on qmy bike erg in addition to my family members. For me it was a bit of a dance getting it shipped out, but if you’re in USA it’ll be fine.
The BikeErg is a basic machine (compared to a peloton with screen), is moderately costly, and makes white noise, but it is good quality and effective. Their rowers are the established standard, and worth considering as well.