1 PC --> 2 Monitors

System currently consists of 2 (Win98/XP dual-boot) PC's with 1
monitor/keyboard/mouse via a KVM which works fine. The monitor is a 1280x1024
LCD.

I have a need to be able to view one of the PC's on 2 monitors though not
necessarily at the same time. The other monitor is a CRT which I want to be
able to run at various resolutions from 640x480 and up which I can't do well on
my LCD.

The 2 PC's have AGP video cards in them now. I have an extra PCI video card
available.

My primary idea is to install the PCI video card into the PC that I want to be
able to use with both monitors. If I go this route, will I be able to set the
resolution of each card independently so the LCD is at its native 1280x1024 and
the CRT is at 800x600, for example? I want to see the same image on either
monitor though spanning the desktop between them would be nice as well though
not necessary. Is this difficult and what's involved? Can/will I have
independent icons in the system tray to adjust display properties (resolution)
for each video card/monitor? How likely are compatibility problems between the
2 cards (ATI All-In-Wonder AGP and ATI Rage PCI)?

The secondary idea is to send the [monitor out] from the KVM into a video
splitter box. This would allow either PC to go to either monitor at the cost
of being able to span the desktop of one PC and having to change resolution
depending on which monitor I wanted to use. Are these splitter boxes any good?
I don't want any discernable degradation in video signal. Does anyone make a
KVM which has a splitter built-in?

Thank you