Buying brake levers, how do I find the correct ones for my bike?
Since it sounds like you have mechanical disc brakes (Avid BB5 or Tektro Novela not hydraulic) then any direct-pull or V-Brake lever should work fine with your cable. Searching for 'V-Brake levers' or 'mechanical disc brake levers' should provide plenty of responses.

For example, if you look at the spec page for the Avid FR-5 lever, you will see that they are compatible with both "Mechanical disc brakes, Linear-pull brakes." V-Brakes are a type of linear-pull brakes.

Note that most levers designed specifically for Cantilever Brakes will NOT be compatible. The key issue is that the levers must be direct or linear pull.  Some brake levers (e.g. Shimano's ST-EF60 shifter+brake lever combo) are switchable between canti's and V-brakes. If you don't set them to V-brake, you're not going to pull enough cable for proper braking.