If I were in your skill/desire window, I would put Aldora Divers at the top of the list.
Devil's Throat is a good suggestion if you can dive it during times when currents are not strong and there are not a lot of boats full of divers all wanting in the throat. While deep (120 feet) by Coz first-dive standards, it's almost a bounce-dive (down, in, up, out at about 70'), it's interesting and with good dive masters it would not be beyond you.
I got certified on Coz and I've got most of my 100+ dives on Coz and I dearly love the place for lots of reasons (dive and non-dive reasons). My favorite dives are the 2nd dives because they are shallow, where all the vida happen.