I currently use several operating systems. One is a Linux system I have which I use for development. One is a Windows system for music composition. And one is a PowerMac G4 400MHz with Mac OS X 10.4. I am getting sick of Windows crashing on me and want to switch my music to a Mac. For software, I use Sibelius 4.1, Garritan Personal Orchestra, and Garritan Jazz and Big Band. My current computer is a Pentium 4 3.2 GHz, 2 GB RAM, with a 160 GB HDD and it just barely suffices. My question is, what Mac would you recommend I get to replace this system? Note, I don't have much money, but I still need to be able to perform everything I've been doing on my Mac system (which eats up a massive amount of system resources on Windows).