lol Frags, seriously man, you better off obeying the law. There is a reason that you are not allowed to hunt with an air rifle...it is not humane. Animals are tough, and can take a pretty lot of holes in them if you do not know what you are doing.
They are right that it is easier to use a shotgun for rabbits, but me, I prefer a rifle. All you need is something small like a .223 (I use the mini 14). Practice on still targets until you are good enough to to snap a 2" at 50 yards, and you should have no problem hitting a rabbit. It is actually not that hard to come upon one while they are standing still if you walk quietly.
The mini14 is cheap to shoot, but if you want something cheaper, a common .22 would work fine also.
There is a reason for making you take gun training BTW Frags, without it you could end up having someone's death on your hands. In the US it used to be that everyone knew how to shoot, and fathers taught their sons (in my case, my dad was also an expert marksman in the Marines :P). It is not the case anymore, and no offense, but an inexperienced person is more likely to hurt themselves or their friend than actually kill game.
Seriously, it is the best way to go.
Also, may I ask what you plan on doing with this rabbit after you kill it? Do you know how to field dress an animal? Skin it? etc.
That is why it is best to first hunt with an experienced individual who can show you how to do all these things.