Any of those will do what you want. For the price, regular Windows laptop is top. A low-end mac is pricier than a mid-high range laptop. If you want to spend the whole 1,000 on a laptop, get a MAC, you can always run Windows 7 on it also. I have run XP on Apple laptops, and it was good, but would not do that on my own money. I'd put the extra $400 towards a new TV or a vacation, or whatever.
Tablet, as you said, it's more for looking than for doing, but with a keyboard setup, may not be horrible. Would be cheaper than the MAC, and would be fun to use. Not great for image editing or large spreadsheets unless you can hook up an external monitor.
I would pick between the PC and MAC. If I really did not care about money, I'd get a MAC with a dual-boot to Widows. The issue with that is that you'll probably spend 90% of the time in Windows and then feel like you spent double the money on a pretty case and the right to go to Starbucks and Whole Foods. Actually, you may also need to buy a Prius for that.