Check out Katathey are lighter
Hi,
I am using Kata HB 207 back pack for 300 f 2.8, 2 bodies, 200 micro, 80-200 and few wides. This is large enough to take in most of the stuff you may need on a trip. I can fit in 600mm f4 + 2 Bodies and few small pime wide lenses in this bag. It is a tight fit for airline OH cabinet.
You can check their smaller one HB 205 for your use. Biggest advantage over Lowepro is that Kata is much lighter in weight and equally durable, mine is 2yrs old now and every thing is intact.