For most people, that is too small. To really make use of higher resolutions, you need a bigger screen. This category includes a CD-ROM drive, a sound card, and speakers. These are a worthwhile improvement over double-speed drives, which should be avoided. The Creative Labs Sound Blaster 16 is an example.
Wavetable synthesis makes the sound of instruments more realistic but costs a lot more.
Speakers, like stereo speakers in general, come in all possible price ranges. The only way to decide on the quality level you need is to listen to the speakers. New home PCs and multimedia kits usually include software. Consider the value, to you, of the included software. A 14.4 Kbaud internal modem is the current standard.