Given that the traffic volumes will be low where and when you say you will be riding, and it sounds like you'll be traveling at modest speeds on those paths, you won't really need one of the more expensive high intensity headlamps. An affordable LED lamp of 150 lumens or more should be enough to be seen on uncrowded roads and to see where you are going. I use the 250 lumen Cygolite ExpiliOn 250, available for about $130. A USB charging capability is also convenient if you need to top off during work hours and don't want to carry the charger with you. I don't recommend a lamp that uses disposable batteries, except as an emergency backup.
If you like to ride fast (>20 mph) in complete darkness, a 250 lumen headlamp is the minimum I would recommend.
For the back, I recommend a combination of a large bright reflector and a Planet Bike Superflash or similar. Big automotive reflectors are best; they are very visible when you hit a bump and your blinky light dies. (And it will - I've had three or four of them of different models and brands fail.) I use two auto reflectors, one amber and one red, on the back of my trunk bags.
Reflective tape/stickers on the back of your helmet, seat stays, and shoes is inexpensive to add.