Do you mean the things that lift the bonnet a little to let more air in...usually by raising the hinges a bit?
Or do you mean bonnet lifters that open the bonnet for you rather than you having to lift it?
If you mean the first bit....don't bother as they are hideous...if you mean the second bit goto LMF Vauxhall...the astra mk3 or possibly cavalier fit the punto as well...they are also all over Ebay.