Two commercial utilities for hard drive formatting are Silverlining and Hard Disk Toolkit. If you can hunt these down on eBay or Amazon, or perhaps see if a vendor like B&R or Wayne's has them in stock, you can format most hard disks just fine, Apple-branded or not.

If you do stick with Apple brand drives, avoid Quantum ProDrive ELS drives at all costs. It's unreliable and also noisier than its more reliable (and highly recommended) stablemate, the ProDrive LPS. Most Apple-branded desktop drives were Quantums (although they did use Conner and MiniScribe in some models, and some PowerBooks used IBM).

1GB should be fine for a 575 unless you plan on doing some heavy duty stuff with it (i.e. Photoshop).