Perhaps the more important question to ask is what am I interested in printing/think I can make a living printing. Are you looking at wedding/stationery? Broadsides/posters? Business cards etc??
Surprised your friends didn’t gush about Vandercooks, since that seems to be a very popular press. The FAG is the Swiss version of the Vandercook. The cylinder proof press (which is represented by Vandercook/Asbern/FAG is great for highly controlled printing (in terms of ink, impression, and register) but they are slow and ill suited for long run work (50 +). Unless you have a fully automatic version, you will be cranking the roller carriage a lot, to the point where it presents an occupational health problem. They are also highly coveted and tend to be more expensive to acquire.
The Chandler and Price, and other platens of similar (Gordon patent) design have their own problems, namely the danger of injury from getting the hands caught in the closing platen. However, they are a much faster machine, better suited for longer runs. They are not as strong for printing large solids, and will struggle with large impressional loads on soft papers (Lettra). Platens are much cheaper to acquire, and are generally more robust if kept up.
So far as the whole starting a business thing? Well, that’s a giant can of worms for sure and I imagine many others are conversing with you about this issue. Best of luck with that.