dont get a powerbook. your wasting your money if thats all your doing. the only reason you would get a powerbook vs and ibook woudl be for the graphjics card, and it doenst sound like you need to spend the extra money on that. and DONT get your extra ram from apple! it is WAY overpriced from them. get some from http://www.crucial.com/
its much much cheaper.
that being said, I love my powerbook. but i play games on it and want it pretty much just for final cut. if it wasnt for those 2 things, i would have a ibook. i dont know about the ibooks, but with the powerbooks, the 15 inch has a backlight keybord, but the 12 inch doesnt. I woudl go witht eh 12 inch though. its cheaper and much easier to carry around and personally, i have no trouble with the size of the screen.
OSX is great. I still use windows all the time along with osx all the time, and I still really see both as abotu equal. osx is really nice to use, but it is buggy, maybe not as much as windows, but it is close. OSX is slightly more enjoyable to use then windows just because of all its built in fetures and once you get used to it, having all the menues always at the top of the screen is really nice. Being able to hide programs while they still run is great and expose is awesome. (you set a hot key and it tiles all the windows currently open and you click on the one you want to go to the front of the others). it makes multitasking very nice and easy. I have not found a shortage of programs and pretty much when compaired to windows, although there is less software, mostly there is alot less shitty software. there is also tones of really usefull freeware for mac. of corse there is firefox which is what i use. there is a free program like ms word (this free program is also for windows and linux). and plenty of other programs that will do whatever you want them to do. if you know how to use windows and can figure out some shit by yourself with windows you will be fine. if not, OSX is easier to learn then windows anyway, for most people. hope that helps.
oh ya, and asside from the really old shit from apple, everything from os 9.whatever and below sucked ass. osx is great though. just wanted to say that.
the next time your about to make a racial slur stop, think about all the delicious foods that come from his or her country and channel your energy towards the purchase of your next international delight.