My OTTB gets Cosaquin and flax seed
My QH gets Select 2 and flax seed
I used to use Smartpak Smarttendon but have found that Cosaquin works better.
I also love Smartpak Bugcheck for summer when the flies are around
As for hoof supplement- I would suggest cleaning the hooves daily and making sure that they are kept dry. My OTTB came with weak hooves and most supplements didn't do any better then me keeping them clean and dry.