Silver metallic is the hardest color to paint, if its your first paint job, aviod metallics and pearls do a solid color, use a base clear also as its more forgiving and easier to paint. Buy a decent gun for around $300 the job will come out so much better. Harbor friehgt guns make great primer guns but suck when it comes to anything else.
Do not use the same gun for primer and everything else. you should have a seperate gun for base and clear also but you can shoot them out the same gun as long as u make sure you clean it really good.
I used paint from thecoatingstore.com on my truck and it came out very good for the price, ive shot dupont and ppg and really like the kemfx paint at the coating store and will use them for all my stuff from now on.
use a resporator there only 20 dollars and you figure out if your health is worth 20 dollars?, your compressor is on the small side and you will have to keep stopping to let it build up to shoot the next panel itll work but will get to be a pain.