I would look at the job market for RNFA in your area. Your hospital needs one now but about when you will finish school? Are you there several RNFA positions in your hospital meaning that there will likely be opportunities then? Do other local hospitals hire RNFAs? I ask this because I also really wanted RNFA as well, but found that in my area there are very few opportunities if any. Also, if there ever is an opportunity, they only pay RNFA pay when you are actually needed to assist, not all the time.
So basically, if you really want to first assist, go for it but realize positions may be very limited. A BSN will open more doors as far as moving up the ladder. I also love the OR and don't plan on leaving either, so I chose the Education MSN route with hopes of becoming an OR educator.