Please help see if this is good inverter - Flin Energy

HI All

I am a long term member of this forum but only visiting occasionally for help

I used to have an off grid setup which failed spectacularly in my old house due to my own non-monitoring laziness and using cheap inverters like su-kaam/luminous 250$ for a 3.5KW pure sine wave whose inbuilt charger was reading 1.5v lower and hence overcharging batteries  & not so great batteries (nontubular / c5) and I learned a lot however in the process and I am hoping to not make the same mistakes twice.

I actually sold all my old panels/inverter and batteries for scrap/cheap price and now looking to start fresh and do less mistakes this time.

In India there is not a lot of choices when it comes to Inverter/MPPT chargers , the big brands like Xantrex will be insanely expensive due to them being imported (duties //shipping ) causing them to be priced 200x of USA costs.

My essential mostly resistive loads ( only fans/lights & mobile chargers alone will be 1000w total but in reality only 500 being used during power cuts  ).
my optional loads like computers/ refrigerator would be another 800w which I MAY NOT really use solar power for but would be nice to keep them in the inverter so they are safe in case of voltage spikes and I get time to turn them off.

I am trying to get an inverter/batteries twice the actual need to be sure I never ever need to worry about using more than 50% of any of those.

Thanks to BB & other great guys in this forum I actually know how to size the loads and the basics of PWM/MPPT,

Today I am going to need some advice on picking the right inverter., I stumbled upon these on Amazon India site and they seem to have good reviews .

I am very very skeptical however before buying one of these because they are insanely cheap for what it does,

Do you think these ( probably chinese products with an indian label) can handle atleast 60% of their rated specs? can they pack an inverter/charger and MPPT and even grid tie circuit for this cost? 

Looks to me the system's cost will be like 1/4th of the setup if I go with all amercian or internationally recoginized brands,

Please help see if you can find something obviously wrong or see if I setup a 5Kva inverter and use only like 1500-1800watts I should be fine

Offgrid with direct solar inverter:

http://www.amazon.in/FlinSlim-MPPT-Solar-Hybrid-Inverter/dp/B00QP46BEO/ref=sr_1_cc_7?s=aps&ie=UTF8&qid=1493043629&sr=1-7-catcorr&keywords=flin+energy

Approx : 1100 USD

OnGrid / Hybrid:

http://www.amazon.in/FlinInfini-5kW-48V-Smart-Hybrid-Inverter/dp/B01MUNQJ3D/ref=pd_sbs_86_1?_encoding=UTF8&refRID=164VAR8K6TCH2W7YTHJ5&th=1

Approx 1500 USD 

I did not consult with my local power agency to ask if they allow the feed back to grid but mostly sure they do.