How much money are you looking to spend? There are the budget units for $100 or less or you can get into the electric units that launch with the push of a button. I think the least expensive of those units start at $200-$300 and go up for there. I started shooting clay targets 2 years ago and went with the first group I mentioned and am happy with it. I just take my units out to the desert and use them by myself. I went with the Trius One Step first and it works great for what it was designed.
http://www.lymanproducts.com/trius/1-step.php
Since then I also picked one of these.
http://www.lymanproducts.com/trius/birdshooter-2.php
I use a 25 foot cord attached to the Birdshooter unit to trigger it from the side at a distance. I also have the Birdshooter unit set up to mount on the spare tire of my pickup. This keeps the unit anchored while I use it. Trius makes a good quality unit.
Cary