[woodfire]

The location is in a finish basement which will have a small enclosure 3'*3'*4’ high, hiding sump pumps and drain pipes to the outside. It is recommended to put the pumps on two different circuits; one will be on an existing 20amp circuit using 12/2 and is running 3 receptacles protected by a 20-amp breaker. The first receptacle is on another wall and the second receptacle is inside the enclosure. Which I will switch out the receptacle and add a 15-amp gfci to use with one of the sump pump and the gfci also will control the third receptacle outside the enclosure along another wall.
. The only other close by circuit is a 15 amp circuit 14/2 on 15 amp breaker running a 2 gang box and a wall switch operating a light fixture from the unfinished part of the basement. I will add a 15-amp gfci to the gang box; I would like to tap into this and run a line to the other pump with another 15-amp gfci in the small enclosure. It’s kind of a straight shot in to the enclosure.
Or, one other option is to cut into a 12/2 circuit on the unfinished basement side, which is controlling 4 receptacles in the other part of the finish basement, and add a junction box and run another 12/2 lines to the enclosure and hook up the 15-amp gfci, which will run the second pump. Would this be a better way to go? If this gfci tripped would it shut down the other 4 receptacles or jut itself. Is it the last in the line or first in line?
More work and wire on this option.

[InfoJunkie4Life]

Can you draw a diagram and upload it?

[mcme]

I would go with the straight shot as it is a) on another circuit b) can handle the pump as there isn't much else on it and c) it's a straight shot.