Now this is a can of worms since whm doesn't have a definitive bis.

Accuracy wise, you can get 600 accuracy (100% hit rate) with food (urchin loaf +40 acc) and melded gear. You don't need accuracy on weapon at all, if you want to blow up some money you can also make pentamelded accessories so you can use spiced cider for more piety. If you want to save money just stat your weapon for acc.
Though max accuracy isn't exactly needed since WHM isn't expected to dps on endgame, so if you miss a few stones nobody will kill you for that, you'll still have a pretty decent hit rate with just accuracy Vs across your body gear. Melding some vit Vs also make your life easier on the last phase of A8S.

Other stats, DET is crap 120 det won't affect your healing or dps on any relevant matter. Crit is by far the best on every class right now though its always a risk due rng. Spell speed is kind of meh, 120 ss isn't enough to impact hots that much, some theorized that 800+ ss makes aero I hit as hard as stone III but there isn't much more than theory on that. 120 piety gives you ~+3k mp per 10mins of fighting since pie increases your regen rate and assize returns.

Personally the best is pie/crit then you work your way with accuracy with melds on your gear, this setup gives you enough accuracy to dps without negative returns, except for your wallet ofc since getting melded accessories might be pretty expensive, loaves aren't cheap either.