How to compare two SFCs, one in thrust, the other in power (both turbofans)?
For comparing turboprops vs turbofans, you would normally divide the turboprop's SFC by the prop's thrust coefficient at comparison airspeed.

For two turbofans, always compare TSFC. It's a function of airspeed and altitude too, but the curves can be found in the paperwork, and for common engines online. 

Jet engine SFC is rarely mentioned and has few practical applications outside of engine design and engineering. All the customer (pilot, etc) will see is thrust.

The FJ-44's TSFC is right there on the wiki page you've linked. The entry for 44-4 is n/a, but you can generally assume it about the same among the variants. The actual vatiance is within a couple percent.