Well, my heads were advance, and came complete. Cams, cam bearing caps, lash adjusters, valves, valve seals, springs, retainers, rockers.
Literally complete, reman heads with warranty (excluding overheating, for which there are caps/dry sensors that indicate overheating). Bolt them on. $400 plus core EACH. I did both since one was bad and may as well match them for the best performance. Frankly, that is a deal. You wait 3 days for them, maybe a week, but they are good to go no questions asked, unlike the possibility of yours needing this that or another part to be rebuilt, which can quickly become $800 a head in parts.
Choose the path of least resistance.