Well, if you really like the Amiga and AmigaOS4 is a thing you would like to use then a PPC machine wouldn't be that bad. Wether an old CyberstormPPC card or a new PPC machine is more difficult to answer. I suppose the added speed is cool with a Cyberstorm PPC in an A4000 even for those classic apps, all in the same machine with possibility of running AOS4 , but it's kind of expensive and newer PPC machines are much faster, so you decide. It's still probably less expensive than a new PPC machine. And you'll probably be able to sell it for the same price you bought it if you decide to upgrade. Beware that the CyberstormPPC could die I guess, because they're getting older and they seem to be sensitive cards or something. I think a more sensible option would be to have a Classic machine like the A1200 with an 030 or 040 for that Classic felling and a new PPC machine ( now or wait a bit) for AOS4.
[EDIT] Ok there's MOS and Pegasus too to be completely imparcial, eventhough to say the truth things don't seem to be going well there.
