[Perfectlap]

You probably need to invest in a real buffer and buy some menzerna intensive polish I and II. It will get the paint as free of imperfections as you're going to get it short of repainting. I've seen some real miracles with a porter cable orbital buffer and menzerna. There was one 993 Turbo restoration thread in one of the forums that a detailer in Spain put out. Really amazing. The paint was a total mess before. Looked brand new after a good 10 hours of work.

As for the white specs, if those are chips those can be minimized as well. There's a technique where you use the back of a nuber 2 pencil eraser. You take a 3 hole punch and cut out piece of 2000 grit sand paper, glue it to the eraser. Sand the chip hole by turning the pencil into the hole so that is flat. fill the chip hole with touch up paint (Langka paint pen), enough that it forms a little paint pimple. Wait an hour or two for it to cure and then take the 2000 grit sand paper and sand it down so its flush. Voila. You then wax the surface with an acrylic wax with fillers.
If the specs are just contamination it will come out with the proper amount of torque from a porter cable or Cyclo polisher ($130-$200).

As for waxes of choice, I think it often depends on the owner. If you're a guy who is cleaning the car every week you don't need a very durable wax so really any autostore wax (Meguiar's, Mothers, etc.) or boutique brand(Poorboys, Zaino, Klasse) will do. If you only wax once or twice a year you should use a more concentrated wax which the boutique brands tend to be. The autostore stuff is usually watered down a bit to throw in some of the idiot factor for a novice.
If you look in my garage cabinet I've got one bottle of every imaginable brand of car wax and my conclusion is that they all give you 99% the same result. Some are very expensive some are just as concentrated at bargain prices and some are just cheap and require a bit more effort but will give you the same end result. The key is to do allot of claying, paint cleansing and swirl removal before you even begin waxing. If you spend 20 minutes waxing you should be spending twice that amount of time claying and cleaning. Swirl removal is almost impossible by hand without spending hours.