You don't have to redeem in the same cabin both ways, which makes sense if you're short of miles.

Take the direct flight ATL-LHR (or is it LGW?) using www.newclubworld.com overnight and return on the day flight in economy or premium economy (though you'll miss out on the BA lounges, which would be shame).

It's worth familiarising yourself with the BA product; sure, it costs a little more, but you get quite a bit more bang for your buck than the carriers on which you've been used to flying.

Here's a great trip report from Sydney in Club World to give you a flavour of what to expect:

http://www.flyertalk.com/forum/trip-...ge-w-pics.html