Like I said I got scammed at the start as well...but we live and learn...
Try the Basic version first, there really isn't that much difference between the two, if basic works for you well then consider the Pro version...
Also please be aware that Pro will not weed out the viruses for you, whilst Limewire has no viruses or spyware within the program you still need to be aware that the network is full of the things....
This Sticky will show you what to look out for on the gnutella network...
* WARNING: Viruses on network you should be aware of! *