What is your budget? I would consider some fstop bags. They are very popular around here, also extremely high quality.
http://fstopgear.com/ That is if you have a high budget. If you want to look at something cheaper I would consider Lowepro bags, I use a flipside and I like it alot. Also very high quality.
http://www.lowepro.com/ Another idea would be to buy an ICU for your normal backpack. (something that divides your backpack into different areas.(Also sold on F-stop's website) Hope this helped man. I would extremely recommend a lowepro flipside, it works amazingly for my fits all my gear perfectly, and helps prevent things from getting stolen.