While not wishing to upset I think in the case of airbrushes and spray guns you get what you pay for and ultimatley the amount you pay is or should be reflected in the amount you are going to use it .
If this is a once a year useage go with a Badger airbrush as they have great reviews and are at a good price. I stand to be corrected here but can have a limited life span.(depending on useage)
If its going to be used quite a lot its well worth spending money on a decent setup in the first place as it will pay for itself over time and will keep on going and producing excellent results.
I myself use an Iwata TR2 airbrush and a Devillbiss spraygun primarily as the latter although expensive lasts a whole lot longer than the cheaper B&Q jobbies and this is my livelihood I am talking about !
The airbrush I have is only used for hobby use but gets used on average about 3 times a month on both mine and friends models so it was worthwile paying that bit extra for it , it also comes with a built in moisture trap which is something you will also have to think about as you dont wants drops of water coming from the compressor onto your paint job!
My compressor at home is nothing more than a Wolfair 25l tank one which delivers plenty for my useage at home. I cant rememebr the price of it but think it was around £200 give or take a few quid.
The airbrush pictured below cost about the same ! But it was money well spent in my opinion due to the use it gets.
HTH and if you want anymore info just ask away
Oh and who was after cork rings ? Try this one go into a motor factors and ask them for some cork gasket material and you can cut as many as you like at a much better price
Shane