Well, for the time being I would suggest to go for G14/3 or G14/2. Although its undeveloped but will very likely be commissioned soon. It's a CDA sector and is on a very good location and for investment purpose, it is the best at the moment.
E-12 -without a doubt is on supreme location. The development may start in 5-10 yrs, of course its a guess but it will develop ultimately and will not definitely linger on for more than a decade.
The best part about CDA sectors is even if they are not developed, they don't lose face value and prices rise steadily (inflation aspect may not be covered).
I personally am not a big fan of private societies, even though CDA has always been pathetic and sluggish but still once something is made, it rules the market and your money is genuinely secure.