You have a 4'th option.
Wait
The new "next-gen" miners should start hitting the market in the next month or two.
thats more speculation than anything else. no prototypes have been shown no specs released, not even a hint of a maybe release date.
Bitfury has 3 videos showing their new chip, including specs. No miners yet though.
Innosilicon has released specs for their A4 Scrypt miners and chips, but not yet on the A3.
BW.com has released specs on their B11 (apparently in production but not for public sale yet) miner and it's chips, and estimated specs on their next-gen chips, but the current miner isn't any better on specs than the S7.
Date and price is definitely speculation, but it's looking pretty solid that SOME new miners will be getting released before the next Bitcoin halfing in July.
I would be SHOCKED if nothing "new" showed up in Bitcoin miners before fall - technically the B11 would count as it's not being sold to the public yet, but I would still be shocked if it was the ONLY thing that showed up for sale before fall.
Oh yeah - the X11 miner showed up for real (one of the big review sites had a review on the one they got), but only a small quantity in the first batch - no idea when their next batch will go on sale.
S7 won't be dead after the halfing, nor will the B11 or Avalon 6 - but their profit will be totally reliant on VERY VERY cheap electric, and small even then, unless a LOT of earlier-gen miners get turned off for being unprofitable.
Up side on the 14/16nm full custom generation - it CAN'T get outdated in less than a few years, as it will have reached the current semiconductor "state of the art" - this is THE BIG CHANGE from anything that came before. There might still be room to tweek designs for smaller gains, but those gains if any will be much much smaller than a "new generation" has generally demonstrated.