elwd,
I have a Dell P-3 600 with Win98, 384 Ram. It works fine in AHII with two upgrades. I've built a few computers since my 386 25mhz days, but I took the easy route this time, simple plug and play basically. For the same money you can get much better performance than these, but would involve more work. Here's two options:
First get a good video card like a 9600 XT or FX-5700 Ultra. Check prices at Newegg, the 5700 Ultra is $159, the 9600 XT $150. Don't spend more on a vid card as it will be CPU limited, it's just a waste of money.
Try that. If doesn't work well enough:
Replace your P-3 800 with a Powerleap 1.4 Celeron. This is incredibly easy to do. You just pull the 800 out and stick the 1.4 in. Go to
www.powerleap.com . Click on products> Slot 1, the 1.4 Celeron is $119. I'm 99% sure you have a Slot1, but you need to make sure.
For less than $300 you're rolling. I have the Poewerleap Celeron 1.4 and a 5200 Ultra, works fine AHII with the sliders in the middle.
2) Get a new mobo/cpu/vid card/memory. Frys has an in store combo this weekend of AMD 2800 and mobo for $159, 512 memory $85, and an ATI Radeon 9800 Pro $199. .
Total just over $425. Far better performance than option 1, but this is a hell of a lot more work than option 1!