I went with 35% in the front, matches if you don't look too hard. To match close to perfect, you need 15%, but for me that's too dark for driving at night and will likely get you a ticket eventually.
I went with 35% 3M Color Stable instead of ceramic, it has a lifetime warranty against fading and turning purple, has good heat rejection. $150 out the door, I paid a little more than some shops because this shop is highly rated and doesn't remove door panels to tint.
$200 or so will get you 3M Ceramic, which will have an even higher heat rejection for the front windows.