Hi and welcome to the forum.

I will comment on the pistols on your list that I am familiar with.
For your first hand gun. If you are looking to keep your prices down and still have a quality purchase I recommend the Glock 17. They are supposed to have the new Gen 4 models out in the next month or so and they are supposed to be an improvement on the Gen 3s which in my opinion are fine pistols.
Next is the Walther P99. Particularly the P99AS. Is a fine gun but about 250 dollars more than the Glock.
Remember that these guns are striker fired and have no manual safeties on them. The Glocks has a trigger safety. These guns as all pistols must by law, all have internal safeties. But the best and most important safety is the one between your ears. Keep the trigger finger off the trigger at all times until you are ready to fire. Remember that and its all good.

As a new shooter I would go with the Glock 17 it is an excellent pistol and very easy to use and maintain. The latest G-17, which is to be released in February 2010, will have interchangeable grip swells, ambidextrous magazine release button and slide stop. The gun is very reliable and requires little to no maintenance. For the money it is the best pistol out there.

The Walther P99AS already has ambidexterous mag release, is very easy to take apart, has 3 different grip back sizes, shoots smooth, feels comfortable and is very accurate (as is the Glocks & others Im sure)...Yes its more pricey, there are other pistols out there less expensive, I bought mine for $730 all said and done...damn glad I bought the P99...I love it...also has picatinny rail under the slide for light/laser combo, not sure about the others but Im sure a few do have it...This also comes with 4 front sights to adjust height, and has adjustable rear sights (left to right)...have fun shopping...decisions decisions!!

In my opinion you should be asking what type of 'action' you want before the brand of pistol. Some brands specialize in particuler actions. Once that's established, then look for a make and model.

Actions-
A) -Striker-Fired
B) -DAO
C)-DA/SA
D)-SA