I know this thread is from a couple months ago, but I figure letting you guys know might still help.
KD's is a great store, but some of the employees aren't. I live maybe 7 miles down 70 in lakewood ranch, so it's the closest store to me. Despite the one bad experience I had with an employee there, it's a great store. It's on the small end, but it's cool. Their livestock is always super super healthy looking, and to give you an idea of prices $25 for 3 heads of frogspawn. Not bad. As far as bradenton goes, they probably are your best bet.
Now Sarasota is a different story.
All of those are a bit of a drive for me, but it's worth it.
Coral Connection is a nice little store. Guy reminds me of an actor for some reason. They have a variety of average to high end corals. I've been a few times, but never bought anything.
Seascape Aquarium and Pet Center- Now these guys are over in Gulf Gate. So a little further. The store itself is definitely dated. The tank stands are noticeable worn down, but the livestock is good. They're an ORA retailer, so you can find some nice stuff. They have a kick-*** Red Sea display in the front.
There are a ton more over there, but these two are my go toos.