Given your proposed routings, you might also want to consider the following option as well: http://www.bestflights.com.au/cgi-bi...indetails=2071 - this is a standard B class European return flight ticket, which allows routing via both hemispheres (so in essence a RTW).

It's valid across QF and BA codeshares too, which could ease some of the round-about travel you'll otherwise be suffering (as for instance QF codeshares on Gulf Air from Singapore to Bahrain, and on from Bahrain to both Dubai and Athens). Within the US there's also plentiful QF and BA codeshares on AA, enough to take care of pretty much every routing you've listed.

On the downside the inclusion of Athens and the date of departure may conspire to make it a more expensive option for your purposes, but it's still quite a handy and flexible fare (and it would be rare to have availability issues in B class, which sometimes pops up in L class).