“I’ll be able to put up with Vista and all its flaws.”
You were rational till that sentence. Why pay and suffer Vista when you can get Ubuntu for free? (they will even mail you the CDs for free) I use Ubuntu on an old Dell laptop and the performance is twice that of a Windows machine (Thinkpad) with twice the hardware resources (MHz, MB RAM).
If you do want to send some money to Redmond, at least get a XP.