Hardware suggestions for Ardour?

I am currently a Linux user who is thinking about switching to a Mac, and would like to continue using Ardour. What kind of hardware (processor type/speed, sound card, etc.) should I be looking at for a Mac? Let’s also assume that I can’t afford the absolute latest Mac there is.

Typically, CPU speed has more effect on plugin count than any of the other items you mentioned. The exception would be virtual instruments, which make more use of ram. I’m new to Ardour, but this seems to be the case with all DAWs that use the CPU for DSP processing.

Okay, I’ll be a little more specific.

Let’s say I acquired a PowerMac G4 at 500 Mhz (I haven’t acquired anything yet). I tend to work with 8-10 track recordings and add 1-3 plugins (usually TAP EQ and TAP reverb) to each track. Besides processor speed, would one or more of the following items allow me more plugin capacity?

  1. More physical memory
  2. 7200 RPM SATA hard drive (whether with or without a SATA PCI card)
  3. A professional level sound card, like the M-Audio Delta 2496 Audiophile
  4. A video card with more video memory