WHAT IS A GOOD SKYPE PHONE TO USE WITH AN APPLE POWERBOOK G3 LAPTOP?

WHAT IS A GOOD skype phone TO USE WITH AN APPLE POWERBOOK G3 LAPTOP?

We have bought a Voip /Skype pluscom phone but it isn’t compatible ( although the seller said it was ), So we then tried it on windows laptop and it still wouldn’t work, rubbish. Anyone know of a better one ?
Great answer thanks, we have OSX 10.3.9, and yes its a fab laptop, but have to get a phone to use from Spain to here…….