The mixer is good... can't tell if it's got phantom power though.
If not, it'd be a good idea to trade up. Phantom power is needed for certain microphones like the Rode NT-1. If you don't have it, you'll have to provide power from somewhere else which is a bit of a pain.

The mic/cables..etc.. deal would be ok but you might want to consider whether you need all the stuff they're offering. Do you need 3 mics? If not, put your money toward a single, better one. Secondly, that mic stand is kinda cheap. They're really lightweight and useless with heavier mics. (with the boom fully extended, most mics will topple the stand over)
Seems like most of the deal they're offering is 3 mics you don't need, 3 mic cables you don't need and a cheap mic stand plus a couple of average monitors. The headphones are kinda cheezy too. Get a pair of AKG K240.

The sound card looks excellent. Actually might be overkill if you don't need 8 inputs. I'd double check to see if there's something less expensive with less inputs.

As far as the amp goes, I'm basically talking about something similar to a home 'stereo system' for your studio. The thing that amplifies your music so that you can hear it through the speakers. You could buy powered speakers but they're generally not as good as a decent amp and a pair of good quality monitors and you'd have to buy a separate headphone amp.

For instance, this amp:
http://www.audioinvest.no/luxman/products/l_l430.htm
.. with these speakers
http://www.paradigm.com/Website/SiteParadigmProduct/ParadigmModels/MonSeries/MonitorSpecs.htm

...would sound incredible and give you an accurate representation of your recordings.