miniflies

I found this forum a couple of days a go and been doing a lot of reading. I think I know which cards to get but wanted to posted and ask for more advice.
I currently have an amex cash back card, and my husband has a mastercard that gives nothing (!). He used to have a citiAA card of which I was an authorized user, and he closed it maybe 8 months ago. We don't stay in hotel much, maybe 3 or 4 times a year, and we fly BA once a year (for a route AA is not good at) and Korean Air once a year. We like to do the BA trip in business class and Korean is always on coach. We usually fly Jet Blue domestic maybe 3 times a year, but if we were using miles we'd go with AA. We have recently used all our AA miles and have nothing left. We have some miles on Korean and some on BA, but not enough for awards.
Now, what to get?
I definitely want an Amex card so I thought to apply for the Starwood one. Question is, should my husband just apply (since he currently has no amex) and get me as authorized user, or should we each have our own?
I also need a visa or mastercard. I originally wanted to get one that gives miles on BA, since those business class tickets are $$, but Im not sure about sign up bonuses on this one and the citi AA card 75k bonus seems great. Not sure if we qualify, because my husband had it before, but maybe I will cause I was only an authorized user? And if we both qualify, again, should one of us get it and authorize the other or should we each apply individually?
Or should I be getting any other cards instead of those? Any advice is greatly appreciated!
Thanks!
Mini Flies