The sling shot in the picture is a Dankung jungle hunter ii, its only really designed to shoot looped tubes. If you would like one to shoot both styles then I would suggest the Dankung panther
http://www.catapults.co/panther.html (I'm actually looking at adding one to my collection myself.) It is designed to hold both grip styles and is also designed to fire both bands and tubes. I personally prefer tubes as they have a longer life before they break than bands and are very easy and quick to change when you're out. I know bands are more powerful, however I have made a kill with double looped 1842 tubes and believe you me they're more than powerful enough to take out small game.
Hope I helped in some way