You should look at possibly getting this ticketed through AA as it will reduce the cost by a few hundred Dollars potentially. Also, have you looked at a DONE4 from a cheaper location? The price might not be that much more.

In terms of Frequent Flyer program the question is what you want to achieve and how your flying pattern will look like in the future. In other words, do you want status or award flights?

If award flights is what you want, L fare like a LONE5 do not accrue that much with most programs. If you are lucky you get 100%, often only 25% or nothing at all. In my experience Finnair has a good program for when flying L class as they give 50%-100% for many flights.