Food for 1 cat with GI issues and another with urinary issues

I'm trying to find a food that both my cat and my partner's cat can safely eat. My cat has some GI issues (frequent vomiting and a sensitive stomach in general), and my partner's cat has a history of urinary crystals. My cat is currently eating Ziwi steam-dried chicken along with some tiki cat wet food (usually a variety of things, but mostly chicken based), and his cat is currently on hills urinary care.

A couple of options I found were Purina ProPlan EN Gastroenteric and Royal Canin Urinary SO with hydrolyzed protein.

Any thoughts or suggestions?