Mickey,
I am both a PC and a Mac user, and don't have a particular bias toward either platform.
Having said that, there is so much more happening on the PC side with music, that if money is an issue (it always is) and you really don't NEED a Mac, you can do more with less with a PC, and it is easier and cheaper to upgrade sound cards, processors, memory, etc. For instance, there is ntrack for $35 (www.ntrack.com), the Windows drivers for sound cards are usually more up-to-date, etc. You have much more flexibility and that usually means more features for the price. You have to be more educated, since you are not locked in to one hardware vendor. For many people, that comfort is key. For a commercial PC (vs. one you assemble yourself), you may have to know either what's inside or be able to test it before you buy.
Some people think the Mac OS is inherently more stable. I think it depends what you do with your computer--I've crashed them all! (bad karma?). I was a dedicated Mac fan until I worked with SawPlus32 (www.iqsoft.com) which is a 32 track professional recording program written in "handcoded" Assembly Language on my brother's Windows computer. That last feature is key, since the whole program is
only 1.5 MB! It has never crashed, supports Microsoft DirectX and Cubase VST plug-ins, and doesn't do anything outside of the SAW folder to your PC. (This is professional software--it has a learning curve, but if you are comfortable sitting in front of a console you will pick it up right away. You get free updates for life, and if you want to upgrade, you can do so for a fee from one version to the next). A trial version of this and several other programs comes with the Darla24 card. (There is a 64 track, 24-bit SAWPro which I am saving up for). SAWLite is $300.
I am not saying that the SAW programs or any other programs are the solution for you--I am just saying that if the software and the computer are carefully constructed, it doesn't matter what format you use, since the final products--audio CDs, MP3s, DAT, etc., aren't OS dependent. (Wav files perhaps the exception). The difference between PC and Mac has become more academic with time--and I say this typing this on a Powerbook G3! Some people get very excited about that, which is good, since the die-hards probably kept the OS alive in the pre
-Imac/-Ibook dark days.
If you go the PC route, check get a program like EchoReporter (download from Echoaudio) to be sure that your new computer can handle digital audio. Take it with you and test out some machines before you buy (other manufacturers have similar utilities on the web). Some non-Intel systems have trouble with IRQ routing and the hard drive should be fast enough (the SCSI vs. IDE arguments seem to have evaporated if the rpm is 7200). A program like this should do it for you, and if the store won't let you check it, walk away.
Either way, you can be "Poised for Greatness" or mediocre...with great sound. Computer digital lets the mediocre of us correct some of our mistakes, like rephasing microphones by sliding one track around to hide or bad mic placement, etc. I think this is one of those decisions where you decide what you are all about--how much of the guts of the computer do I want to have to deal with. Lots of plug-in potential means more flexibility, but it won't replace your outboard equipment.
Don't be in a hurry, surf the web, and check the archives--there is a lot there. Best of luck.
To the rest of the group--don't flame me, it's only one man's opinion....