I've always reused the original head bolts.
I save my money for rod bolts and main studs. Never blown a head gasket, ever.
After 2 builds on same heads, they checked flat within .001
Thats over an 8 year period.
Once you have your stuff milled flat, its good unless you overheat the heck outta it or need them smaller.
One thing that can be nice is the smaller 12 heads.
To your direct question...
bolts are my recommendation.