I don't know of one that combines just those two things, but SmartPak has a number of multi-purpose supplements. SmartCombo has joint, hoof, coat, and digestive supplements all in one. It's not one that I've used personally, though.
We give Acey SmartCombo II and I believe it's been very beneficial to her. Her hooves are rock solid, her joints no longer "pop" when she firsts starts working, her coat is like a shiny penny and we've had no digestive issues. :). Overall, we think it's worth it. :) Posted via Mobile Device
What do you mean by 'multipurpose' exactly? As good diet & nutrition are basic 'ingredients' of health, as joints & hooves, etc are part of the whole horse, a good quality 'complete' supplement or otherwise appropriate supplementation *that balances whatever their particular diet is* should be 'multipurpose', if I understand what you mean by that.