I put the 3 Johnson Pumps on mine last spring - 2007 SSV 22'. Each pump had the 1" intake. Well worth the money.

It was a couple of weekends b/c I did not have full days to work on it. Not sure about the cost b/c I got new bags also.

All 3 pumps are mounted under the back seat. I had a cooler/storage compartment under the center seat of the boat. They fit under the seat, in front of the vdrive/tranny. Each to access.

I added the 750# sacks in the back - each had 1 pump.
I put a new bow bag and kept using the center locker bag on one pump. A "Y" value controls what bag gets filled for the 2 front sacs.
All bags are vented from the top.

I might redo the plumbing on the bow bag. Presently it fills & drains on one side of the "V" shape. Thus when draining, it only drains on one side. I'm left with a bunch of water in the bag - drains about 2/3 of the water. I have to manually lift the one side to get the water to move to the other side to drain. The redo will have 2 hoses to fill and drain the bag - each side of the "V". I should have enough hose left over, but I will need a Y-Fitting and a quick connect fitting for the bag.

Mark