I'm not a GPU rig expert, but I can speak to the AntMiner comparison. Assuming you were to purchase from Bitmain's next available batches, I would go in this order:
AntMiner L3+
AntMiner D3
AntMiner S9
While everyone is drooling over the D3 right now, the rewards are far too difficult to predict this far in advance. The next available batch will likely be for December - which is an eternity from now in crypto-time. The L3+ on the other hand has proven to be a much more reliable and steady earner - especially if you're mining lesser known alt-coins using an
automatic profit switching pool. The difficulty spike has already occurred and the profits are much easier to predict. The AntMiner S9 is only a good option if Bitcoin remains high, but it still isn't nearly as profitable as the L3+.