I'm a moderator at the Power Tab Archive forums and was an administrator at the old Power Tab Archive website and all I can say is this: what you're asking for is difficult to find. The Power Tab Editor is a wonderful editor and since it is free is highly coveted. The absence of the once 10s of thousands of tabs (since its closure due to the HFA
et al) makes it almost useless. You could try popping in at the forum
and asking if anyone has the tab you're looking for. There are backups of the entire archive floating around.
In the meantime ASCII tabs from the other sites are plentiful ... and pitiful. As for software I now use Sibelius First. There is a handy GuitarPro app for iPhone/iPad that will show tabs and allow you to make basic tabs but it, too, has a fee (nominal, IMO).