Well, the LanParty Ultra-D has good onboard sound, so you really don't need a sound card (unless you're a hardcore audiophile).
A decent set of speakers will do you well.
A good LCD monitor is worth its weight in gold. I can hardily recommend the brand in my sig, but there are many great brands... BenQ, LG, NEC, Philips, ViewSonic. Even Dell's LCDs are good... but steer clear of their PCs lol. Widescreen monitors are perfect for watching movies, but sacrifice height to acheive the width.
Things to look at in LCDs:
- Screen size - go for the biggest you can afford (19" is a good sweet spot)
- Response time - the smaller the better for gaming... shoot for 8ms or smaller
- Resolution - 1280x1024 or better. LCDs should be used in their native resolution.
- Constrast ratio - the bigger the better
Keyboard/mouse - Get at least an optical mouse. If you're not a gamer, look at some of Microsoft's or Logitech's keyboard/mouse bundles (optical or laser mouse). Wireless or wired is for personal preference.