If simple is what you're after, you could also consider installing a venturi Injector. You install it in your piping (after filter on your return line) and you let the flow of the pump draw in whatever chemical you want. They are used a lot with ozone systems to deliver a stream of ozone gas into the water but work just as well with liquid fluids. You can look them up online as well. The only additional equipment you'd need is a shutoff valve and, possibly, a metering valve to adjust fluid flow.

Anyway, just some ideas to consider. There's tons of ways to skin the cat of injecting chlorine. Just depends on how fancy you want to get. Good luck with your setup and, if/when I get approved for forum access as PF regulars (I'm still awaiting registration approval), I'd love to see your final setup.