Personally i love zilean but i hate his squishiness and high dmg.. id rather be tanky/fast and not ks. What is a support that is fast/tanky and doesnt do alot of dmg.. I main Tank zilean and i highly prefer it over ap since bronzies dont go tanks they go carries every role - Lee jg Fiora top kal adc ahri mid pretty much xD
If your MMR is low enough for you to be matched with Bronze, then chances are you shouldn't really be insulting your own people. As for tanky supports: 
all fit the quota.
Basically any champion with a hook is freelo at lower ELOs because people 1. Suck at dodging skillshots 2. Get too close and simply forget you have a hook.
I have never played Blitz but his hook is insanely good and his ulti can break a teamfight. He also has the best laugh.
Thresh has everything you want in a support: Utility with the lantern and hooks, takiness, and also kill pottential with flay and ultimate.
Nautilus is just FREELO. People just walk into you and expect you not to have your q for some reason. If your ADC is competent you should get a lot of kills with something like this Q-----EW-------Auto and your adc finishes them off.
His dives are also AMAZING. His ult is pretty much a guaranteed kill against any ADC that is standing undertower.
Examples: Ultimate----Q----EW-----Auto plus ADC damage.
If you are skirmishing you can go
Q------EW----------Ulti-------Q again and E again.
