Bike bag help

Hi there - I am currently working in the US and bought myself my first road bike when I moved over here six months ago. I'm pretty hooked on it now (I normally ride mountain bikes back in Scotland) and don't want to sell it before leaving. Therefore I'm planning on bringing it back on a plane with me in ten days.

So... what I need is advice on good bags which you can recommend which will ensure my bike survives the flight (well two flights - one on United and one on British Airways). The cheaper the better but I want to make sure it survives! I think I prefer the idea of a padded, soft bag rather than one of those hard-case types.

Also, if anyone has any idea of on-line bike shops over in the US (like Chain Reaction, Wiggle, etc) where I could purchase said bike bag that would be great aswell.

Any help, tips, tricks to avoid airline charges would be also be appreciated.

Thanks a lot.
Rob