Its pretty hard to get a good finish unless you do it in a spray booth. If your planning to use acrylic paints you may get away with a compressor at home, be careful about fumes etc. If you want a 2PAC finish take it to a pro. the paint will cost $100+ per litre (at trade prices for good paint) and you'll need 4 to 5 litres at a guess. depends how many coats you want and how well the surface was prepared. 2PAC can only be done in a proper spray booth. 2PAC is the paint used on all new cars (from about 94 on wards on the commodores, i can only comment on what i know). Its generally the best finish. But basically unless your garage magically stays at 24 degrees with good ventilation you wont get a good finish.