Hello. I'm in the market for a new computer (a laptop, for certain), and I was considering buying a high-end PC (I have a black MacBook right now). I've been wanting to experiment with Unix-based OS's (for developing mainly -- I'm a developer/programmer -- but for other purposes as well). I'd like to install on one of my computers a bunch of different Unix-based operating systems. I'd like to install and be able to run a few different ones, such as Solaris, two or so different flavors of Linux, and maybe BSD. I was considering installing these OS's on either my current MacBook or the new high-end PC I'm considering.

However, I've recently considered buying a cheaper laptop strictly for running Unix OS's. If I decide to take this route, there's some things I'd like to know about, if anyone can help. First off, the computer I would buy would be cheaper (unlike the $2500 to $3000 PC laptop that I'm considering), but I don't want it to be that cheap (probably $500 minimum and $1500 maximum -- that's just an idea though, I'm open to anything).

If I bought this mid-level laptop (and I definitely want it to be a laptop), would it have to a PC, or does someone in the market for a computer for Unix systems have other options besides the standard PC vs. Mac? Are there other computers out there (maybe ones just for Unix or something) that I might consider, or would I definitely want a PC?

Also, how cheap of a computer can I get away with and still have "full" functionality with the things I want to do? As I mentioned, I will mainly be developing on it, so most or all of the things I install and work with on the computer will be related to development. I will want to try out developing on each of the OS's I install on the computer (Solaris, BSD, GentOS Linux, other Linux's, ect.). What kind of specs will I need to achieve this? I can figure out what type of hard drive space I want for myself -- I'm mainly concerned with how much RAM I will need, as well as what type of processor / how much processing speed/power I will need.

Any help here will be greatly appreciated. Thanks in advance!