"I recently got myself a new setup:
AMD3800+ (dualcore)
2 Gb of ram
250 Gb harddisk
GeForce 6800 GS videocard, 256 Mb
Phillips 200W 20"" widescreen monitor (running 1680x1050)
I
love the big screen. All of the other specs are just a matter of how
much money you are willing and able to spend on it. I got a pretty
sweet deal on this in my local computer store.
The dualcore
processor (basically 2 processors on a single socket) allows me to do 1
processor-heavy task (VNS rendering for example) and all my usual
'office' stuff next to it (browsing, email, lighter apps). Haven't
tried 2 processor-hungry apps at the same time yet, but it should work
just fine.
If you're doing maps, a big screen is a must. One of my clients has the 30"" Apple Studio display and it is
gorgeous! Mind you, he told me that on some projects he lost 20% of his time scrolling around.
As for Mac vs PC, I'm not going to go into that (not enough Mac experience to make a good judgement)

"