Here is complete components I am planning for,

X2 ELF 88mm
Original Airbot Omnibus F4 Nano V6
Hakrc 15A Blheli_S BB2 2-4S Dshot 4 In 1 ESC
HGLRC Super Mini 1.38g WS2812 Colorful LED w/ 5V Active Alarm Buzzer
4 Pairs Gemfan Hulkie 1940 1.9x4.0 PC 3-blade Propeller
4 PCS Eachine Prop Guard 1102 1103 1104 1105 Brushless Motor
Flysky FS-A8S
ORANGE 850mAH 2S 30C/60C (All 4 motors draw maximum 20A,  lipo  0.85x30=25.5A. Is lipo ok for this build?)

As per sepcs from above components, its coming to 99.3g AUW (93.3g if I drop prop guards).
There is ORANGE 360MAH 2S 30C/60C as well, If I use that AUW is 78.3g. But that lipo 0.36x30=10.8A only. Wont that be an issue?
I am aiming for maximum fligt time rather than speed. In fact I prefer to fly slow.

I reviewed all x2 elf 88mm builds at https://rotorbuilds.com/part/11208 out of 22 builds, 10 are using 1104 7500KV. 
I do have the option of buying Racerstar 1104 7000KV and 1103 8000KV. 
As per specs, 1103 with 3s and 2030 prop it has 78g pull and 4.7A load current. 1103 is 3.7g and can take 1-3S
As per specs, 1104 with 2s and 3020 prop it has 95g pull and 4.1A load current. 1104 is 5.5g and can take 1-2S 

Which one I should go for?

Given the choice you are presenting, I would opt for the 1104's.  Honestly would (and did) opt for 1105-7500kv (you can opt for the 6000kv ones) like the Dragonfly's.  I am running these with 2.5" props and they land ALOT cooler than the Eachine 1104-6000kv's.  They endure the strains easier and mine have been super reliable.

(05-Sep-2018, 03:58 PM)kaitylynn Wrote: Given the choice you are presenting, I would opt for the 1104's.  Honestly would (and did) opt for 1105-7500kv (you can opt for the 6000kv ones) like the Dragonfly's.  I am running these with 2.5" props and they land ALOT cooler than the Eachine 1104-6000kv's.  They endure the strains easier and mine have been super reliable.

with X2 ELF 88mm I cannot run anything more than 2 inch props.

(05-Sep-2018, 04:48 PM)sim_tcr Wrote: with X2 ELF 88mm I cannot run anything more than 2 inch props.

They will spin 2" props beautifully.  The original Frame I had was a 95mm "X" that was limited to 2" props, 1.9" really.  The 1105's worked perfectly.  When that frame broke, I tried a 110mm frame, still limited to 2".  Broke that frame, 2 actually before settling on the 125mm frame that is The Bug now.  It accommodates the larger 2.5" props and the motors have handled them well, but the motors originally were for a 2" craft.

You will not have to re-motor if you go with a larger frame in the future is all.