flowers to give

A friend just called about an hour ago asking for my suggestion on what to give her significant other this coming weekend, you see it's her natal day and he wanted to make it a lot more memorable than her previous celebration because it also marks their wedding anniversary. So the good friend in me suggested on throwing out a surprise party with close friends to be invited and plenty of foods to share. Plus make the day more lovelier by sending her flowers, which he can give personally or through floral arrangements service. He loved the idea! and my ears are flapping! I'm such a good planner eh?! But the hassle comes in when he asked me to order the flowers for him, because he doesn't know what to get and he might get something that her wife wouldn't love. So that makes me busy now by searching for nice flowers to get. Any suggestions? let me know!