I have a Topeak rear rack (actually two, one for non-disc and one for disc) and a Topeak MTX bag that locks/unlocks quickly on the bike. Internet pricing is around $45 for the rack, and $65 for the bag. I am selling the 2 racks and bag for $70. They were used for 3 months and are in perfect shape. PM me for more info and photos.
I like the Topeak and Ortlieb quality. Both are German vendors and can be found easily throughout North America. They have a ton of solutions.
On the lock side, I have a slightly different opinion than most. Buy the lightest and thinnest cable lock you can find. They prevent the casual walk by theft. Anyone who is a serious bike thief will cut through most anything (u-locks/chains, cables) in seconds. There are lots of videos about this. Some folks like u-locks but they do not work in every situation. Cables tend to work in more situations.
Buy a lock that is easy to carry and/or mount on the bike and is easy for you to use. The lock you like to carry is the lock you will use.