Presario 5340 upgrade possibilities

I got a dead Presario 5340 from a friend recently and have been going through it. Appears the HD may have had some issues, and it was only 10 G anyway. Put in a spare 160 G, ran fdisk, formatted, and installed 98ME. Now I'm trying to get drivers for the PCI modem, PCI network adapter (nowhere to be found, and the most important!!!) and audio driver. It's needle-in-haystack looking for this old stuff. PC runs fine, 98ME is great. System doesn't recognize anything plugged into either rear or front USB ports yet, so I can't add drivers via memory stick (that would be so much better than wasting CD's burning drivers that don't work!). Currently the only way to exchange data is thru the CD drive, until I get the network adapter going and can get it online, have DSL, and do a Windows Update.
Also, wondering what hardware upgrades might be possible? Not looking to make a monster out of it - it's a PII !! Maybe max the memory to 384 mb, got 96 now. A CPU would be good, what can it handle, has a PII 400 Mhz now. And maybe a base graphics card, 640 x 480 (and no option) on my 20" LCD is like watching 8mm home movies on an HD flatscreen - HUGE! Any ideas? Wanna keep it low-budget, it's a 2nd machine/playtoy.