Best Stock BB Heads?

I don’t know if you mean heads or templates to sell...... but no matter, I don’t have either.

With how cheap you can buy aftermarket heads these days, the OE head market is very small...... usually someone who has to use them because of class requirements....... or for resto people wanting the car to be correct.
If all you have is a decent set of cores, and fully restore them using all new parts, valve job, guides, ex seats, flat milling, etc...... it’s real close to what a set of Stealths cost.
That’s before any port work is done.

The best advice I can give you on diy-ing some bowl work on a set of OE heads is......... a little less porting is better than a little too much.
Also, the first two things I look at for assessing cores is....... how badly are they corroded, and how bad is the core shift.

Heads done like what’s in the pics, on a 440 built with the right combination of parts, could make 500hp on pump gas.