HI Johnathan,

Not a bag, but here's the lightweight 20 lb Tyros 4 case (with wheels) several of us purchased and recommend:
I recommend this over a softcase as it's only 1 lb more than my previous Kaces Porter softcase w/wheels,
yet offers better protection with strong & ultra lightweight Luan wood & aluminum hardware.
Case is well built with attention to detail.

http://www.synthzone.com/forum/ubbthreads.php/ubb/showflat/Number/330487/