How much time and patience are you interested in investing in the car?
I have done a bit of car painting with Acrylic based paint.
essentially once you get the hang of the spray gun, painting is quite easy to get a very reasonable finish.
What is damn hard is fixing dents so that you cannot tell its there. This take an enourmous amout of patience.
This finish my mate and i achieved in 7 days (drove in the garage on saturday, sprayed the paint on the next saturday, drove out the garage on sunday). Excluding cutting and buffing. This photo is about 3yrs after i painted it.
http://i168.photobucket.com/albums/u166 ... 0sold2.jpgNot perfect, but not too bad either for a backyard job and the first time using a spray gun. Good from far, but far from good. Ignore the bonnet, i stuffed that up...... (sun came over and heated up the bonnet, paint didnt like that). The car was multiple colours before we started so anything was an improvement.
I suggest acrylic paint, as its quite forgiving and i found quite easy to paint, sand the paint down with 400ish till its nice and smooth. get rid of all dents, clean it good with wax and greese remover, start with your putty primer, put that down, sand that back with 400, if imperfections are really small you can just put more putty primer down and sand it back again, else get out the car bog. once its pefect and all been sanded with 400 give it a few coats of colour 2 or 3 (mix it with thinners as per the tin can), dont try and put too much on at once, you can always put more on, but once you get a run its game over. If you are doing metalic paint you put clear over the top, do as many coats as you can in my opinion as then you have more paint to buff back. Just keep going around and around the car with clear untill you either run out of thinners, paint or patience.
I painted some speaker boxes with acrylic paint, was just gloss black, but i put like 10 coats of clear on it as well. I Got that nice piano black finish relatively easily.
Acrylic paint dries dull looking, you need to then wet sand it back with 1500-2000 grit, then you need to buff it with cutting compound. this is also time consuming. But you can get the mirror finish if you work hard. Be VERY VERY VERY careful when sanding near edges, its very easy to take all the paint off a corner.
My spray gun i got from the paint shop, about $80 (is a gravity fed one). The paint itself for a whole car was around 300-400 (metalic paint, clear, thinners). Pluss some other stuff like sandpaper, safety gear (masks), tape, drop sheets etc. its prolly $600 by the time you finish.
The absolute number 1 rule for painting is that paint will NEVER cover imperfections. In fact paint will magnificy imperfections 10 fold.
This is just my experience as an amateur in his backyard weilding a spray gun.