Looks like a decent enough starter kit, the compressor is okay and will do the job. But one with a tank would be nicer to use.
that being said, only bother to upgrade it if you personally find that the one you have isn't cutting the mustard. Things like it getting hot because of running constantly and then spitting moisture due to the heat and then needing a cool off period can be avoided for some time with tanks.
As for airbrushes, I'm a fan of Harder & Steenbeck, I love my Evolution Silverline, and since I got it there has been a new line of triple chromed ones released, pushing the evolution prices down a bit
http://www.everythingairbrush.com/acatalog/Evolution_Silverline.html
I've been happily using the 0.2mm solo silverline edition from that page for over 2 years now, only replaced the nozzle/needle setup once so far, and that was totally my fault stubbing the needle! hehe. However spare parts and seals are available from the same site for all the brushes they sell

find one you like. Can't reccomend H&S enough, the nozzle fitting is so nice and simple (threadless) which I havent seen on any other brushes? Knowing how fiddly those tiny nozzle threads were on my older brushes it was a life saver!
edit; Badger renegade would fall into midrange (rather than top end as you describe) Same as the Evolution I suggested would be midrange. For top end look to H&S Infinity or iWata Custom Micron and drop your jaws at those prices!