To me, Stanton is worth re-arranging the outfield for. JD Martinez is not, especially since they'd be getting very few prime years on a long contract. Not sure about Martinez' ability or desire to play first or DH, but his age strikes me as a train to avoid the contract he wants.
Santana is a good plan B if he is ok with the predicted 4 year deal. I'm no huge Hosmer fan, but I'd take the prime years of Hosmer over the post-prime Martinez.
But I think I'd prefer Moustakas over either Hosmer or Martinez. He certainly has the power advantage. His deal won't be be as crippling. And his defense is actually quite good despite oft-repeated posts that it isn't. Especially since next year he won't be coming off an injury-plagued season.
So my preferences in order
1. Stanton
2. Santana
3. Moustakas
4. Hosmer
5. Martinez.
I have a feeling Dombrowski has a very different order, at least after the top spot...