I am getting everything around to install an automatic ballast system in my 1997 Super Sport and I will be drilling a seperate 1.5" thru-hull on the bottom of my boat for the water pick up. The thing I can't decide is what type of thru-hull should I use. . .a scoop type thru hull or a flat thru hull?

This thru-hull is going to go to a manifold which will have 3 reversible simer pumps hooked up to it. I will be filling and draining all from the same thru-hull. If I put a scoop type thru hull in, will it create too much back pressure when I'm trying to empty the sacs? Also, will it create a lot of pressure when I am pulling somebody and the water is shooting in to the thru hull?

If I use a flat thru hull, do you think the 3 pumps would suck the water up enough to not lose any fill time? Also, where is the best place to get a 1.5" thru hull? Thanks for any help.