capfo,
I have just reread your original post.
I would imagine your priority , at this time, is seat swap. . . . .if that is the case, Ryanair are the simple solution. They need you, you need them. If I understand you need 2 Sims (so 12mths ) & if they are at the standard required you will enter the "Command" process.
Norwegian, well, a little less simple. A whole load of guys who didn't fancy pay -cut /base change to swap seats , who were pretty much "Command ready" in FR, bailed out & joined NAS in Spring 2014 with implied "rapid Commands". . . .it didn't pan out that way, DEC's were recruited continually, & some actually went back, disillusioned by the Salmon Pink Glasses they had donned. Base stability WILL affect you if you have your Command in FR, but, it will hit you even sooner if joining NAS as an FO, the last 2 Winters have seen lots of "enforced" changes, doubt this is likely to change.
I have spent the last 18mths or so , recommending FO's to join FR in preference to NAS, if you had told me this 4 years ago I would have asked that you (or I ) be certified , how times/things change.