Dwight has made it known he prefers NJ. If he hits FA it will be NJ because it will be Dwight/Deron/Lopez/Brooks/Morrow/James + a heck of a first round pick in a deep draft.
If Dwight is traded to NJ they only do so knowing he will sign with them. So either way, especially with Dwight himself saying he prefers NJ, NJ appears to be the more desirable spot. You seem to place way to much emphasis on "world class organizations" and the impact on FA decisions. Spurs are the cream of the crop of world class organizations, have 4 les & and had a superior player to Dirk and still couldn't land free agents. It's about money first and foremost and then team second. Mavs can't offer both Dwight and Deron full contracts. They can get close but D&D will have to leave money on the table to sign with Dallas; that's not the case in NJ. Also Dallas will be capped out and depleted, NJ will still have good talent and a great draft pick.
If its via trade, the point is moot, Dallas has no real shot then and Orlando likely isnt letting Dwight walk for nothing. They are likely not going to trade him to LA due to perception as well unless it's a no brainer lIke Pau AND Bynum. Dallas should hope for ORL to trade with LA because that gets them at least Deron.