Cables are usually included in kits... But, Tektros are not typically a good brake. They are 'cheap' stuff and come stock on a LOT of bikes. Tektro does have a FEW good products, but those v-brakes are just cheap. Plan on spending 30 bucks, plus get a new Odyssey Slik cable for your brakes. If you still need a lever, check some out and pick one that you like and ask about it.

CHAIN TENSIONERS: I think the Haro ones are the best design I have seen. Here is why:
1. They use a bolt that screws into the washer part of the tensioner so there is no extra bolt sticking out of the back of the tensioner like 90% of the other tensioners.
2. They use regular hardware store bolts, so if you lose it or break the head off, you can get a new bolt for 10 cents the same day.
3. It comes with 2 different length bolts depending on how deep in your dropout you run your rear wheel.
4. It has a good sized washer on it to help protect your dropouts better.
5. I have run mine for 4+ years with zero problems.