I'm not a very keen fan of the targeted search idea, I'm afraid. It is true, a tight beam will carry much, much further than a wider one, and of course, a broadcast would be very energy-inefficient and would not carry very far because of inverse square law. But the chances you'll be able to transmit to a star just when they happen to be listening (correcting for travel time of the signal) is extremely unlikely.

Even if you use astronomical surveys to eliminate stars too young for life to have evolved, there would be hundreds of thousands of possible stars within a radius of a thousand light years of any sun. And to have a chance of transmitting to them during a time an evolved technical civilization was listening, is almost impossible. You would have to transmit to hundreds of thousands of stars for millions of years to have even a 50/50 chance to get someone at home. And that's if they were all conducting elaborate and very long term listening programs. Remember, the stars are thousands of light years apart in space, but they may be billions of years apart in time.

IMO, I think the only way SETI would work (not technically, but statistically) is for a transmitting star to be able to generate enough signal power to fill a volume of millions of cubic light years with signal strong enough to stick out above the noise, and it would have to do this for millions of years without stopping. This is much, much harder than just transmitting a tight beam to a single star at the edge of that volume. You have to irradiate enough space to reach enough stars over enough time to have a chance of getting someone to hear you.

I've written a paper with some of these numbers crunched out, using several different estimates of the Drake Equation. If you like I'll email you a copy.

Now you know why I'm an enthusiastic SETI pessimist. The more I think about it the harder it gets.