re 2 monitors:
windows 98 will support up to 9 monitors.
rule of thumb: you need an additional video card for each additional monitor although there are some high-dollar video cards which have 2 outputs. you may have to add ram, too.
check out "help" in your windows start menu. type in "multiple monitors" under the search tab.
check out
http://www.realtimesoft.com/multimon/guide/
i am running 2 monitors. cost: $40 for brand-new 8mb pci video card, $200 for used 21-inch monitor, $20 for generic 128mb ram. be sure to consult your system manufactuer's documentation and website before choosing add-on components.
i do not run any special software such as ultramon or powerstrip, but the registry edit tip under "desktop icons move to primary monitor after reboot" on the realtime soft website was invaluable.
note: make sure your anti-virus software is shut down before installing new video drivers. with norton you have to go into the options screen. this cost me lots of frustration and a long-distance phone call to canada.
caution, a multiple monitor setup is just like a boat or a car or any other machine. i have a 2-monitor setup, but i wish i had 3...
good luck