Considering finances are a bit of a concern for you guys, I would strongly consider the CR1. K1 requires adjustment of status and removal of conditions, both of which add to the overall cost. In addition, it used to be free to file for work authorization when adjusting that status, but USCIS changed that on April 1, so it's a cost and a wait.
I always advocate for people to start their lives together on as equal a footing as possible. Being 100% reliant on your partner from the moment you arrive until your EAD is issued is very difficult, especially for people who are used to a certain amount of autonomy. New country, new people, new friends...it's nice to be able to do some things on your own while contributing to the relationship. Just my 2 cents. Best of luck!