If you love LimeWire for PC then you're gonna get so much in love now that you change to Mac.
It's kinda different the OS transition but nothing to worry about it.
First you need to check if you have installed Safari that's the application you use to navigate on the internet as you should do it in a PC using Internet explorer or Netscape.
If you have installed It. then open it and go to the limewire site and choose the d/l option. as you can see the newer version is 4.10.0
i believe that you're not going to have any problems at all.
If you still having problems send me an email please, so i can be in contact with you to help you.