If you're looking to build just one vintage/retro gaming computer for all your 90's/early 2000s needs, you might want to consider putting together a Windows XP system like this one.
AMD Phenom II X4 945 (3.0 GHz) AMD Radeon R7 240 (2 GB) 4 GB DDR2 RAM Sound Blaster Audigy 0570 Chenbro ATX Case Altec Lansing ACS250/400 speakers Custom IBM Model M keyboard: https://youtu.be/Qb8E1zNwf7E Windows XP Service Pack 3
