Honestly, I had a hard time finding a bag that is versatile enough to fit my various tetris-combination of equipments and how I like it arranged, ease of access, amount of free space available, etc..
In the end, I decided to do the foam wrap method - home made. I bought a yoga mat ($20 for a 1.5m X 0.9m) and I (intend to) cut them to size.. and sew some velcros along.. This way, I can wrap my 450D with various possible lenses attached and dump it into any bag I currently have!
Surely it's going to be alot cheaper than buying those thinner neoprene wrappers selling for 2-3 times the price for a fraction of the material at CP. I probably even have excess to sew a box-shape and put in my haversack - same as any camera bag you can find if you think about it.
It's not the "proper" solution, but I guess it serves the same level of protection and it's good enough for me. Might take a 1-time effort, but definitely gonna save heaps!
The end outcome I hope to achieve is to make it convenient to bring my toy anywhere, using whatever bag I feel like bring for any occasion.
Hope this helps!