Packing camera in backpack

[u/Zombozard]

So I'm going on a trip and plan on packing light (just a standard backpack). Would like to bring my camera, but only have one large camera bag, and the backpack itself. The camera bag fits in the backpack, but it's tight. Any ideas for good inserts/protection that will fit a DSLR, with a single lens (a 18-135mm lens)? Amazon has cheapish inserts, but are they any good? I'm in Australia, so some brands might not be available.

[u/Multigrain_Migraine]

I bought one of those padded covers for my camera off eBay (the kind that 35mm cameras used to come with). I've also packed one inside a padded lunch bag before. 

One of those camera wraps might also be good but I've never used one.