Hi AJ.....I started with exactly the same slingshot many moons ago. At that time the Daisy tubes were great and I killed piles of rabbits, some squirrels, and lots of pest birds with mine. I used lead shot in .31, .38, .44, and .50 that I cast myself. A few years ago Daisy changed the tubing and their bands began to suck terribly. They also cut them too short and this caused undue stress on the elastics and they failed quickly. In the glory days of the old-school elastics I can say that I never recovered a .44 or .50 round ball from a ribcage-shot rabbit as it was always a pass-through up to 25 yards.
I haven't tried a Lazerhawk in several years. The last ones I tried were tapered and were so bad I wrote Marksman a very ugly letter. My reply to you, which is going to probably result in death threats from other forum members, is that if you are wanting to use a factory elastic you could probably get by with the Barnett replacement sets. They also include a set of yoke tip protectors that are very useful and the Daisy doesn't wear these in its factory configuation. I would suggest getting a few sets of these, trim them to length (I reccomend the distance from the tip of your pinky to thumb with your fingers outstretched as far as possible) of WORKING band (from the edge of the pocket to the tip of the yoke. This does not include the band you'll use to hold the tube on the fork.
When you have some time, you should try one of the forum vendors for something a little better, but I can tell you my old Daisy really was the business back when I started with its good tubes and its steady diet of lead round balls. Now I have moved on to chained gypsy naturals, something very attainable for anyone with a pocketknife, sandpaper, and some rubber bands.
Go enjoy your slingshot and when you're ready to try making some there are a lot of good ideas and designs up for grabs on this forum. We're ready to help with advice.
Finally, listen to what Jeff (shot in the foot) says, he's been doing this forever and I have a pile of respect for him and his opinions. He really knows what the real deal is.