size of output and GPH decrease advice needed what pump to get

[sig_1959]

My current pump is barely enough to keep with drain when bypass to sump is fully closed ON 150g. on my 120G I was able to return water back to the sump and close the bypass valve as pump was slowly getting blocked. In this way, I was able to run pump without cleaning for 8 months

This is current Panworld 150
1100gph max flow
28 foot max head pressure
180 watts
1" MPT in/out
Footprint 5" x 12"

I was thinking about getting one with 1750 gph, assuming that if I have enough with 1100gph, 1750 will be more than enough

Panworld Model 200PS
1750gph max flow
39 foot max head pressure
290 watts
1" MPT in/out

but the guys made me thinking again about barracuda Reeflo

ReeFlo Barracuda Gold Pump

Maximum Flow Rate: 4680gph
Maximum Shut-Off Head: 21`
Maximum Wattage: 253W
Average Wattage: 237W
Inlet/Outlet: 1.5"/1.5"
Warranty: 5-year manufacturer`s warranty


I do not know if I need more GPH, since return line will be 3/4 anyway ( I can not change it) and also Reeflo is $160 more than Panworld

I know I am loosing flow when I reduce size from original outlet size and I can not decide is it make sense to get 4680gph instead of 1750, since I will not be able to run carbon reactors with excessive flow returned to the sump
Thanks