All you have to do is play with the placement of the powerheads and you will have areas of low, medium and high waterflow. I have corals that need to be in each area and never had any problems.
I have 2 of them in my 40 and they are great, because they have such a wide spray output. The only thing i dont like about them is they are to big in size for my tank, but in your 75 they will probly looked good.
If your cycle is complete you can go ahead and your clean up crew. After a week of the clean up crew being in the tank go ahead and add one fish. Wait one week or two in between adding fish after that.
I beleive thats the only way you can use that model. I have the one that can be used as a HOB or sump. It didnt work that great as a HOB but work good in the sump.