At least if you had the FAA ATPL you would have around 1500hrs with a full ICAO ATPL which is what most jobs require.
outside of europe, yes. in europe, no.
The FAA ATPL i think is a valuable license to have. But if you don't want to get your JAA licenses, you should plan on most likely not working in europe, which can be great, as long as you don't have a personal problem with it.
I've worked in the US for several years, but i am now converting my things to the JAA system. I would have loved to have stayed in the US, but i wasn't allowed to work there legally anymore, and in other parts of the world it isn't that easy to find a job, since i don't have that much turbine time.
about the ATPL
Be careful also, that for the issuance of an ATPL, you don't need "just" 1500 hours. There are requirements as to the "type" of hours aswell. For instance in the JAA you need 500 hours of multicrew time, and for the FAA one you need 500 hours cross country time (cross country here being a flight to a point atleast 50NM from the point of departure, with or without landing) and other requirements aswell.
So it might be possible, to have 1500 hours but not meet the requirements for the ATPL. Especially people who are instructing in the US, run into the problem of not having enough xc time, even though they have 1500 hours.
And a little off topic,
The added bonus i think of going to the US (or in europe for that matter), and instructing there to build hours is that you learn alot more about flying than you would when bannertowing, sightseeing, (buying hours), etc... It wasn't untill i finished my instructor training that i had the idea i understood everything about the plane, and flying it.