I agree w/Willy about not using the floor tank...it's really poorly designed w/beveled sides and is great at sloshing water out...plus an in-floor-tank is a pain I remember from a friend's Rabalo...it was larger, better sealed, didn't slosh, but a PAIN to retrieve live bait from...
Another way to go w/live bait requires no thru-hull or over-the-splashwell plumbing at all...all it needs is 12 volts and is completely self-contained...fill w/water to get started, plug it in and it recirculates, aerates and filters the water...here's one I made several years back....
It's mostly used for freshwater live herring, gizzard shad and trout, but I've used it many times in saltwater for porgies, shrimp, mud-minnows...no need for all the raw-water plumbing...plug it in and GO FISHIN'!!...
If you want more info on how to do this, or how to buy an already made just let me know...