You seem to be a die hard IBM thinkpad user. They came up with the idea, patented it, manufactor it, and still use it. Many feel as you do that the eraser head is the best mouse for a laptop. I would try looking at the IBM Thinkpads now manufactored by a company called Lenovo. Just go to www.lenovo.com and look at the thinkpads not lenovo's notebooks.
Thinkpads are powerhouse notebooks they are built strong and to last and they do, they seriously are laptops that work hard. and they provide the buyer with the oppurtunity to put the most advanced components in their laptops. However they are more geared towards business even though many consumers and business users alike love the systems. But being geared for business initially they really don't have a home/consumer thinkpad, therefore thinkpads aren't the most stylish notebooks made, traditional black chassis since their first notebook only the material has changed.
If you are dead against the trackpad then I would look at the X series (not the tablet) the X60 does not have a touchpad is extremely light weighing in at about 2.8 pounds with high end components. However it lacks an optical drive. If you need or want an optical drive which many of us do then go for the T60 which does have a touchpad but also has an eraser head. The T60 is lightweight but with more features then the X. All thinkpads have the eraser heads! Also very important because they are business notebooks they are not built with the best video card, if this is important be sure to select the higher end video card when customizing the machine. Good luck.
I want to buy a laptop, however my first and foremost requirement is that it absolutely has to have the eraser/nub mouse thing in the middle. Ideally it would not have a touchpad whatsoever. Is there any site that lets me search by this criteria? I prefer Dell's but it's hard to see on their pictures which one have the nubs and which ones don't. Also I don't think any of them come without the touch pad. I know you can disable it but I will never use it so I don't even want it.