I would go with linux hands down any day. Windows 98 was so buggy it killed me. Every time I opened a program I'd see a blue screen it seemed like. If you do go windows at least go Windows XP. If you go with Linux try
Suse.
Suse has a very easy to use GUI interface that comes bundled with YAST. YAST lets you edit the kernal without recompiling it.
I'd get a MAC before I ever get windows 98 again.