Ok Cardiac, for what you want to do, this is what I suggest. It is only my opinion and I'm sure others will have very good advice.
Compressor - A Twin cylinder like the AS196 (with 3 litre air tank, Regulator, Moisture Trap and Pressure gauge) about 120 UK pounds, should let you airbrush for 45min to an hour before it will need to cool down. On Fleabay or better still at an online shop, you can probably get a kit with a hose and cheap airbrush for this price. Don't buy a compressor without an air tank.
The Single cylinder AS186 about 90 UK pounds, can airbrush for around 30mins before it starts to overheat. Once cool you can start airbrushing again but I don't think this will be enough for your needs.
Airbrush - A Veda (from Pecoglobal.com delivery about 4 weeks) cheap airbrush 0.3mm needle are about 30 quid (a kit will include a cheap airbrush). Better still an Iwata Neo Gravity feed (I have never used one but they are supposed to be a good beginners airbrush and have 2 cup sizes) 50 quid or better again an Iwata Eclipse, you will have to decide which model but I would suggest a gravity feed for your needs, over 100 quid. Badger do very good airbrushes but I don't know much about them.
Paints - Com-Art (Comart) are ready to use straight from the bottle water based acrylic airbrush paints. They are affordable, great and easy to use and can be used on primed metal (probably need varnishing). Kit G is 5 opaque and 5 transparent paints which is a good set to try them out. About 25 UK pounds.
A Cleaning Station - about 15 UK pounds (you can make one by putting a hole in a plastic bottle)
An Air Hose 3m - about 10 UK pounds (a kit will include this)
A Mask - see my videos on the subject (about 40 UK pounds) (can use masks from DIY store for paints, dust only masks are no good)
You get what you pay for, so the more you can pay now the less chance you'll have to buy new equipment in the near future. Believe me, I had to. Get advice from a shop if you can, go to the shop, try stuff out, look at the different options and ask questions to suit your needs.
If you don't have much money buy the cheap options to try out airbrushing but expect to buy better equipment once you decide you like it. Always airbrush with good ventilation (open windows, use fans) and wear a mask.
I have made lots of videos to help beginners like myself and put them on YouTube
Melumental - YouTube
I've never bought from this online shop but Everythingairbrush.com seems to have all the things I have mentioned including cheap airbrushes (not Vedas). You could ring them up for advice and see if you could get a deal.
Good luck and have fun,
Cheers Mel