Picked up two packages today, one of 5 stepper motors (those have gotten cheap!), and one of linear bearings. Alas, I had forgotten to double-check with the sturdy bom, and got LM8UU rather than LM10UU. No wonder they seemed small.
I should also keep in mind that two kinds of ball bearings are used, 7 608's (8mm x 22mm x 7mm) and 4 624's (4mm x 13mm x 5mm). I think the 608's are the kind I already have a small mountain of.
I'm getting the hotbed pieces from nophead after all, getting the necessary pieces from elsewhere would be more expensive and more work after all. I'm impressed with the price nophead has managed to get the kit down to. And they are being very helpful, so I'm happy to throw more business their way.
If you're thinking of making a Mendel90, and customizing it is not what you're aiming for, get the kit. It'll save you time, headaches, and possibly even money.