Can sb please explain me how to use (a low-priced) NAS?

hi there,

I am about to get an Ethernet disk (with USB access) for backing up the data on my desktop (running Win98se - yeah, I know, I know... - and Linux) and my laptop (Winxpsp2 and Linux) but also for syncing small files between them. I am totally new to this world and I would like to understand how things work.

In my ideal world, a dual interface external drive should allow me to
- use the file-system I want
- create the directory structure I want
- being accessible as a web-server without installing anything, and in a way that I could use an open source application as interface
- be accessible via USB2.0 for fast file transfer (possibly like an USB pen, without specialty drivers - but I could tolerate custom drivers for USB access)

Being a thighwad, though, I am looking for an inexpensive item, like the Lacie Ethernet Disk Mini 500 GB (not the home edition, but the one with the USB port for direct connection) which also happens to run Linux. From what I've read so far, these sort of low-cost products come with proprietary drivers and software that could limit the user's options.
Being a newbie, it's not clear to me what can and can't be done.
Can someone please tell me if the following is possible (for the Lacie or for another low budget NAS you know - please specify which one).

1. For sole Ethernet use, can I avoid installing proprietary software or drivers on my PCs?
Moreover, is there an Open Source solution to access the Ethernet disk without manually using the integrated web-server?

2. I've read some systems come with a FAT32 filesystem. That would waste a lot of space and limit max filesize to 2 GB. Can I format to NTFS or, better yet, ext3 (this of course is a question with a different answer according to the particular model)?
Will I be able to access the files in win98, then?
(after all the files that get served to me via the Internet are stored on disks with a filesystem different from FAT32)
Specifically, one review of the Lacie Eth Mini stated that formatting the disk to NTFS would prevent the additional USB interface from working. Anyone with this drive can confirm this?
EDIT: I've read here that version 2 uses XFS and allows one to use both interfaces.
(Win98 won't work since the drivers are not supplied for this OS)

3. Can I alter the directory structure, deleting the "myMusic", "FamilyStuff" and the other default folders on the disk and still be able to access my newly added folder structure from the device web-based interface?

Well, that's all for now.
I hope someone will find the time to read all this and shed some light on my ignorance.