Not to be disrespectful ... I don't believe we have enough information to make a qualified recommendation.
How much sailing experience do you have? In what sized boats?
Have you sailed cruising catamarans?
Can you handle the sails
on a 50 foot catamaran
at sea, in a storm at night.... alone?
I've been sailing these type of boats for a while and become uncomfortable at anything over about 44'. Granted, I'm probably a lot older than you but we have to remember, when things go bad at sea, they go bad all at once.