Nice research and findings Mr. Imran Bhatti. Impressed.
Let me share my experience about the usage of Batteries;
I bought VOLTA 85 AH x 2 for my 2KVA Sinewave Inverter, these batteries died in 6 months, back-up was only 15 minutes.
Then I bought AGS 95 AH x 2 and these are still working even after 3 years.
Yes, Atlas AGS batteries are expensive than others, but these are best, I guess.