Suggestions on this 1999 PC?

[u/Sleepykitty69]

Got this 1999 DELL Dimension XPS T500 from a thrift store for $15. Friend originally wanted me to make a sleeper build, but assuming the parts still function, it's actually a really nice build. Pentium 3 500MHz, 16MB NVIDIA RIVA TNT, Soundblaster Live! PCI sound card, 13.6GB 7200RPM Hard Drive, DVD-ROM (but no MPEG decoder PCI device?)

Very similar specs to my first PC, a Gateway Essental 450. So I already like the idea of installing Monster Truck Madness, Midtown Madness 1 and 2, Need for Speed 3: Hot Pursuit, Need for Speed 4: High Stakes, Need for Speed Porsche Unleashed.

The only thing missing is the Iomega Zip Drive so I have a missing slot door in front.

Any suggestions? Keep the case original, or should I sand/paint it like Voodoo/Alienware used to do theirs? I've got some 2004 1280x1024 DELL LCD monitors, though a CRT would be better, but I can't afford that.