I've got a Macbook, it works perfectly. It sounds like the programs you are using aren't too intense, I often run Photoshop, Illustrator, InDesign, Safari, at the same time, sometimes even Parallels, AutoCAD and a few of those.
If those are the programs you're running, 2GB ram should be plenty. Thats what I've got and I can use all of those memory-intense programs.
If you want to save money and not get Office for Mac, you could get iWork 08. It's compatible with Microsoft (sometimes you get a message that a certain font hasn't carried through, but thats not a big deal, if you are using it for an aesthetic layout and you absolutely need your specific fonts, you can export as a .pdf). iWork is a lot cheaper, and you can get a family pac for only $20 more (allows installation on 5 computers instead of 1), so if you have a friend who is buying a Mac as well you can split the cost. For a single copy iWork runs about $80.
If you need to run any windows only programs there are plenty of options like BootCamp, or Parallels. I use Parallels, it allows you to easily switch between your mac side and Windows side, within seconds, no need to restart.
My dad has had an iMac for 3 years, no problems yet. My fiance and I have each had Macbooks for a year, no problems either.
Also if you are a student (or have a son/daughter, nephew/niece who is), Mac offers great deals over the summer. I think right now it is free $100 printer, and free iPod touch with a Mac purchase. And if you're in Canada, you can get airmiles from airmilesshops.ca. If you're in the states I think mypoints.com offers points on purchases.